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ULTRASONIC STUDIES ON MOLECULAR INTERACTIONS IN
CERTAIN BINARY AND TERNARY SYSTEMS
THESISTHESISTHESISTHESIS
Submitted to the
UNIVERSITY OF MADRASUNIVERSITY OF MADRASUNIVERSITY OF MADRASUNIVERSITY OF MADRAS
in partial fulfillment of the requirement for the award of the degree of
DOCTOR OF PHILOSOPHY DOCTOR OF PHILOSOPHY DOCTOR OF PHILOSOPHY DOCTOR OF PHILOSOPHY
in
PHYSICSPHYSICSPHYSICSPHYSICS
by
P.A. ABDUL MAHABOOB, M.Sc., B.Ed.,
Under the Guidance of
Dr. T. IRUSAN, M.Sc., M.Phil., Ph.D., Dr. V. KANNAPPAN, M.Sc., Ph.D.,
Supervisor F.I.C.S., F.A.S.C.,
Reader in Physics (Retd.) Co-Supervisor P.G. & Research Department of Physics Reader in Chemistry Presidency College P.G. & Research Department of Chemistry Chennai – 600 005 Presidency College, Chennai – 600 005
Post Graduate and Research Department of Physics,
Presidency College (Autonomous), Chennai – 600 005, INDIA
NOVEMBER 2006
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ACKNOWLEDGEMENT
‘Gratitude is a rare flower which only noble hearts pluck to offer it to God’.
With grateful hearts, I acknowledge with gratitude, the innumerable graces and
blessings I received from the Almighty and for His guidance throughout my life.
I consider myself very fortunate to have Dr. T. IRUSAN, Reader (Retd.),
Post Graduate & Research Department of Physics, Presidency College
(Autonomous), Chennai – 600 005, as my research guide. It is my great
pleasure and duty to express my sincere thanks for his guidance and advice for
the successful completion of this thesis.
I wish to express my heartful gratitude and respect to my co-guide
Dr. V. KANNAPPAN, M.Sc., Ph.D., FICS, AIC., Reader, Post Graduate &
Research Department of Chemistry, Presidency College (Autonomous),
Chennai – 600 005, for having suggested the present investigation which has
immense practical applications in various branches of science and for his
committed inspiring guidance and constant encouragement. His deep interest in
research, his humane touch and positive approach have made my period of
research an educative one.
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I wish to thank Dr. S. JELANI, Deputy Secretary, UGC, (SERO)
Hyderabad and Dr. P. RAJAGOPALAN, Former Dean, College Development
Council, University of Madras, Chennai for the award of teacher fellowship
under FIP for two years.
I express my gratitude to Dr. S. Ramanathan, Principal, Presidency
College (Autonomous), Chennai for providing the necessary facilities for
carrying out my research.
I acknowledge with gratitude the Management, the Principal,
Mr. A. Khader Basha of The New College, Chennai, for allowing me to carry
out the experimental work in the college.
I owe my special thanks to Dr. M.G. Mohamed Kamil, Head of the
Department of Physics, The New College, Chennai, for his constant support,
encouragement and allowing me to do my research in the department. I also
thank all the staff, teaching and non-teaching members, in the department for
their cooperation, help and encouragement.
My sincere thanks are due to Dr. R.K. Natarajan, Head of the
Department of Physics, Presidency College (Autonomous), Chennai, for his
support shown during my research work.
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My special thanks are due to Mr. S.J. Askar Ali, Senior Lecturer in
Chemistry, The New College (on FIP), for his brotherly and friendly support
which made my research easier.
I acknowledge with gratitude Dr. M.M. Abdul Kamal Nazer, Reader in
Chemistry, Dr. T.K. Shabeer, Reader in Chemistry and Mr. A. Khaja
Mohideen, Senior Lecturer in Chemistry, The New College, for their valuable
help and encouragement rendered to me in various ways, while doing my work.
I wish to thank Mr. S. Chidambara Vinayagam, Mrs. N. Indra Gandhi,
Mrs. B.S. Shanthi, and Mrs. K. Parameswari, Teacher Fellows in the
Department of Chemistry, Presidency College, for their support and
encouragement. My thanks are also due to Mr. Y. Christurajan and
Mr. P. Balu, Research Scholars in the same department for their help and
encouragement. My special thanks are to Mr. M. Vanjinathan, Research
scholar, Department of Polymer Science, University of Madras for his help and
cooperation. I also thank Mr. M. Arunkumar and Mrs. G.S. Gayathri, M.Phil.
students in Chemistry, Mr. B. Aijaz Mohamed and Mr. K.T. Shameer, P.G.
students in Chemistry, The New College, for their help.
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I express my gratitude to Dr. (Sr.) R. Jaya Santhi, Reader in Chemistry,
Auxilium College, Vellore, Dr. S. Mahendran, Reader in Chemistry, and
Dr. D. Roop Singh, Reader in Chemistry, Presidency College, for their
cooperation and help. My special thanks are due to Dr. S. Jayakumar, Reader
in Physics, Vivekananda College, Dr. Shanaz Ahmed, Head of the Department
of Physics, JBAS College for Women, Chennai and Mrs. P.E. Akilandeswari,
Senior Lecturer in Physics, JBAS College for Women, Chennai for their support
in carrying out my research.
My special thanks are due to Mr. S.L. Balaji, A. Thirumal Marugan,
Mr. P.M. Khaleelur Rahman, Mr. A. Rahmathullah, Mr. K. Basheer Ahmed,
Mr. S.M. Abdul Aziz and Mr. Md. Kaleemuddin Sayeed for their
encouragement and support.
I am grateful to Dr. A.K.W. Anwar Ali, former Head, Department of
Physics, The New College for his cooperation and support. I also thank
Dr. B. Kamalaharan, Dr. M. Shanmugam, Dr. P. Sivakumar,
Dr. U. Ponnambalam, former Heads, Department of Physics, Presidency
College, for their support and cooperation.
My sincere thanks are also due to Dr. G. Md. Farhathullah,
Dr. M. Jailani, former Principals of The New College and
Dr. R.S. Raghavan, former Principal of Pachaiyappa’s College, for their
encouragement to carryout my research.
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I also thank the teaching and non-teaching staff of other departments of
The New College and Presidency College for their support in various ways. My
thanks are also due to the store keepers of both the colleges for their
cooperation and timely help.
Thanks are also due to the Trustees of ILM Educational Trust, Chennai
for their cooperation and invaluable blessings.
My heartful thanks are due to my departed paternal uncle
Mr. P.A. Khaja Khaleel Rahman, for his blessings and constant
encouragement, without which this project would have been very difficult. I
record my sincere gratitude to my parents Mr. P.A. Akbar Ali &
Mrs. S.M.A. Mymoon Akbar, my wife Mrs. S.A. Shabnam Mahaboob and my
uncles (Late) Mr. P.M. Sheriff Ali, Mr. P.M. Syed Aminuddin, Mr. P.M.
Basheer Ahmed, Mr. P.M. Abdul Sathar, Mr. S.M.A. Shahul Hameed and
Mr. S.A. Abdul Azeez, and my aunts and all my relatives for their prayerful
support and help, which guided me in all situations.
P.A. ABDUL MAHABOOB
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Dedicated to:
All the Members, Relatives and
Friends of
Penna Family
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CONTENTS
Chapter Title Page Number
1. Introduction 14
2. Experimental methods 57 3. Theory and calculations 69
4. Ultrasonic investigations of molecular interactions 83
in binary liquid mixtures
5. Determination of stability constants for the charge transfer 121 complexes of certain hydrocarbons and iodine in n-hexane solution by ultrasonic method
6. Determination of stability constants for the charge transfer 159
complexes of certain hydrocarbons and iodine monochloride in n-hexane solution by ultrasonic method 7. Ultrasonic studies on the charge transfer complexes of iodine 195
and certain phenols at 303 K 8. Determination of stability constants for charge transfer 238
complexes of iodine monochloride and certain phenols at 303 K 9. Determination of the formation constants for the charge 280 transfer complexes of certain ethers and iodine monochloride in different solvents 10. Summary 321 Annexure 328
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LIST OF ABBREVIATIONS AND SYMBOLS USED IN THIS THESIS
C : Concentration
U : Ultrasonic velocity
ρ : Density
η : Viscosity
κ : Adiabatic compressibility
α/f2 : Absorption coefficient
χU : Molecular interaction parameter
τ : Relaxation time
Lf : Free length
Vf : Free volume
πi : Internal pressure
CE : Cohesive energy
Z : Acoustic impedance
Va : Available volume
LJP : Lenard Jones Potential
UE : Excess ultrasonic velocity
ηE : Excess viscosity
κE : Excess adiabatic compressibility
VfE : Excess free volume
LfE : Excess free length
ZE : Excess acoustic impedance
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VaE : Excess available volume
∆G : Gibb’s free energy of formation
∆G# : Gibb’s free energy of activation
CT : Charge transfer
K : Formation / Stability constant
α : Polarizability
µ : Dipole moment
ε : Dielectric strength
Fig. : Figure
BZ : Benzene
CTC : Carbon tetrachloride
BBZ : Bromobenzene
CBZ : Chlorobenzene
MCL : m-Cresol
OCL : o-Cresol
PCL : p-Cresol
PL : Phenol
PYR : Pyridine
IO : Iodine
IC : Iodine monochloride
MST : Mesitylene
PXL : p-Xylene
MXL : m-Xylene
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OXL : o-Xylene
TL : Toluene
ANT : Anthracene
BIP : Biphenyl
NAP : Naphthalene
CVL : Carvacrol
DPE : Diphenyl ether
CAN : 4-Chloroanisole
ANS : Anisole
DOX : 1,4-Dioxane
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CHAPTER - 1
INTRODUCTION
This thesis deals with the measurement of ultrasonic velocities,
densities and viscosities of binary and ternary mixtures to understand the
intra and intermolecular interactions between the molecules of components.
Excess thermodynamic parameters are calculated for certain binary systems.
In ternary systems, the stability constant values are calculated for the
donor-acceptor complexes using the nine aromatic hydrocarbons as donors
and iodine and iodine monochloride as acceptors in n-hexane solution at 303
K. The main aim of these investigations is to investigate the effect of structure
of donor and acceptor on the stability of this type of complexes. The stability
constant values are also calculated for the charge transfer complexes of four
ethers and iodine in four different solvents of different polarities. Similar
investigations are also made with iodine monochloride as acceptor with a view
to study the influence of solvent properties and acceptor properties on the
stability of this type of complexes.
The study of molecular interactions and the variations in these
interactions due to structural changes has been carried out by various
experimental techniques such as infrared1, nuclear magnetic resonance2,3 and
Raman4 spectra and dielectric property measurement5. The complete
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understanding of the nature of intermolecular and intramolecular interaction
may not be possible by any single method. A number of workers have
reported the study through ultrasonic method6-10.
The successful application of acoustical methods to physico-chemical
investigation of solutions has become possible after the development of
adequate theoretical approaches and methods for precise ultrasonic velocity
measurements. Lagemann and Dunbar11 pointed out the sound velocity
approach for the qualitative estimation of interaction in liquids. A parallel
measurement of sound velocity and density of solution allows one to obtain
information about their volume, elastic properties and changes in their
properties. Complex formation in liquid mixtures has been extensively studied
by ultrasonic methods by many workers. The formation of hydrogen bond in
solutions and its effect on physical properties of the mixtures have received
much attention.
1.1. ULTRASONICS
Ultrasonics is the science of acoustics and the technology of sound.
The frequency range of ultrasonic waves is greater than 20 kHz up to several
MHz, which is beyond the audible limit. The upper limit for gases is around 5
MHz and for liquids is 500 MHz. Low amplitude waves are more pronounced
at frequencies between 2 to 10 MHz. The waves whose frequencies are lower
than the audible limit are called infrasonics. But human ears do not respond
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to either of these frequencies. The ultrasonic technique is used for different
investigations due to the following advantages:
• At higher frequencies, the high absorption coefficient values are
easily measurable.
• Shorter wavelengths occur at higher frequencies, so that plain
wave conditions are more easily realized which is especially
important for the smaller specimens.
• Frequencies associated with relaxation phenomena often fall
within the ultrasonic range and therefore they can be easily
focused.
The study of acoustics had its beginning with the Greek philosopher
Pythagoras in 600 BC. He laid the foundation for the use of stringed
instruments, which are notable contributions to the science of acoustics. It is
believed that Galileo was the first to start the modern studies of acoustics. In
1638, he showed that pitch is associated with vibration, which was
considered to be the second milestone in the science of acoustics. He elevated
the study of vibration to scientific standards by successful correlation of pitch
with frequency of sound source. Investigations in high frequency waves did
not emerge until 19th century.
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The era of modern ultrasonics began only in the early twentieth century
with Langevin’s use of high-frequency acoustic waves and quartz resonators
for submarine detection in 1917. From then on, slow but steady progress was
made in the measurements of propagation constants of materials. Early
landmarks included Pierce’s quartz-driven ultrasonic interferometer12 in 1925
and the discovery in 1932 by Debye and Sears and also by Lucas and
Biquard of the ultrasonic diffraction grating. An important event during
1930s was the pioneering work of Sokolov in 1934 on ultrasonic flaw
detection.
Ever since, the field has grown enormously with wide applications in
science, medicine and other areas. Graff13 investigated physical, chemical and
biological effects of ultrasounds on macromolecules, microorganisms and
cells. Stokes14 made the first attempt in medical imaging using ultrasonics.
The explosive rate of development in high frequency digital and
computer techniques has opened new avenues for using ultrasonic
equipments for laboratory study and industrial purposes15-17. The
applications of ultrasonics in various fields have been illustrated in fig.1.1.
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1.2. PRODUCTION OF ULTRASONIC WAVES
The devices that generate and detect ultrasonic waves are called
transducers. Active transducers or transmitters are those that convert
electrical energy into ultrasonic energy and passive transducers or receivers
are those, which do the reverse18-21. Transducers use any one of the following
techniques: (a) capacitive, (b) magnetostrictive, (c) electrostatic, or
(d) piezoelectric devices22,23. The various transducers are listed below.
• Magnetostrictive transducer
• Electromagnetic transducer
• Pneumatic transducer
• Mechanical transducer and
• Piezoelectric transducer
1.2.1. Magnetostrictive Transducer
In 1847, Joule19 observed that a change in length occurs in a rod of a
ferromagnetic substance such as nickel, when a magnetic field is applied
along its length. This change in length is proportional to the strength of the
field and is irrespective of the direction in which the
field is applied. This effect is known as magnetostriction.
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1.2.2. Electromagnetic Transducer
This type of transducers uses attractive forces of electromagnets, which
are used to generate vibrations. They are used for obtaining high amplitude
vibrations at frequencies usually below the ultrasonic range.
1.2.3. Pneumatic Transducer
Pneumatic transducers such as whistles are useful at frequencies
extending to a lower ultrasonic range to produce small particle sprays of
liquids, which may be used in burners, coating materials and certain type of
bulk cleaners. They are also used to dry materials and to break up foams
obtained from various chemical processes.
1.2.4. Mechanical Transducer
The mechanical transducers are devices, which are actuated
mechanically. They are used to obtain high amplitude, often-high intensity,
vibrations at low sonic frequencies. A typical example is the sonic pile driver
in which counterbalanced eccentrics are used to generate vibrations in a
direction parallel to the axis of the pile.
1.2.5. Piezoelectric Transducer
This is a widely used method for the generation of ultrasonic waves. In
this method, a pair of opposite faces of a piezoelectric crystal is subjected to
pressure, which develops opposite electric charges in other pair of opposite
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faces. The sign of the charge changes when the faces are subjected to tension
instead of pressure. Curie brothers in 1880 found that certain crystals like
quartz, tourmaline and Rochelle’s salt will develop electric charge, when
mechanical pressure or tension is applied on the face of the crystal. Their
experiments showed that there is a certain relation between the mechanical
pressure applied and the nature of charge developed, and the sign of the
charge changed when the pressure was changed to tension. Quartz crystals
have been widely used for generating ultrasonic vibrations in solids and
liquids, since they possess high mechanical impedance.
1.3. DETECTION OF ULTRASONIC WAVES
Ultrasonic waves propagated through a medium can be detected in a
number of ways24. Some of the methods employed are given below.
1.3.1. Kundt’s tube method
Ultrasonic waves can be detected with the help of Kundt’s tube. At the
nodes, lycopodium powder is collected in the form of heaps. The average
distance between two adjacent heaps is equal to half the wavelength. This
method cannot be used if the wavelength of ultrasonic waves is very small. In
the case of a liquid medium, instead of lycopodium powder, powdered coke is
used to detect the position of nodes.
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1.3.2. Sensitive flame method
A narrow sensitive flame is moved along the medium. At the position of
the antinode, the flame is steady. At the position of the node, the flame
flickers because there is change in pressure. In this way, positions of nodes
and antinodes can be found in a medium. The average distance between two
adjacent nodes is equal to half the wavelength. If the value of the frequency of
the ultrasonic wave is known, the velocity of the ultrasonic wave through the
medium can be calculated.
1.3.3. Thermal detectors
This is the most commonly used method of detection of ultrasonic
waves. In this method, a fine platinum wire is used. This wire is moved
through the medium. At the position of nodes, due to alternate compressions
and rarefactions, adiabatic changes in temperature take place. The resistance
of the platinum wire changes with respect to time. This can be detected with
the help of Callendar and Griffith’s bridge arrangement. At the position of the
antinodes, the temperature remains constant and the resistance of the
platinum wire remains constant. This will be indicated by the undisturbed
balanced position of the bridge.
1.3.4. Quartz crystal receiver
Just as quartz or Rochelle’s salt crystals are used for the generation of
ultrasonic waves, they can also be used as detectors of ultrasonic waves.
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When ultrasonic waves are incident on quartz or a Rochelle’s salt crystal,
alternating electromotive force of the same frequency as the ultrasonic waves
is generated. This voltage is very small in magnitude and a radio frequency
amplifier can be employed to amplify the received signal, which may be
detected by a superheterodyne receiver and displayed on the screen of an
oscilloscope. This is the universal method for the detection of ultrasonics.
1.4. REVIEW OF THEORETICAL ULTRASONIC STUDIES
Ultrasonic velocity is an important and essential physical parameter
having structural dependence. Kneser25 proposed the first theory of
ultrasonic absorption in liquids. Depending on excess absorption
phenomenon, Pinkerton26 gave a useful classification in liquids. Several
theories were proposed to study the ultrasonic velocities in binary and
ternary mixtures. They are Flory’s theory27, Jacobson’s free length theory28,
Schaaffs’ collision factor theory23, Junjie’s empirical relation22, Nomoto’s
equation29, Narasimhan and Manikam’s combined equation30, Vandael ideal
mixing relation31, Patterson theory33 and Flory-Patterson theory27,32,33. These
have been recently used34 to obtain the ultrasonic velocity in quaternary
liquid mixtures. These theories have been tested35. Based on the additivity of
internal energies, the sound velocity in a liquid mixture was determined by
Kudriavstev36,37. But the above theories do not explain in detail, all the
phenomena of ultrasonic wave propagation through liquid media and also the
state of individual components in a mixture.
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Ultrasonic velocity measurements are used in understanding the
molecular interactions in pure liquids and binary / ternary mixtures since
the deviations from the linear dependence of velocity and compressibility on
the mole fractions provide an insight into the physico-chemical properties of
liquid mixtures such as molecular association and dissociation as well as the
strength of interaction between the components. The molecular interaction
studies have been made on liquid mixtures. The non-linear variation of
velocity and other thermodynamic acoustical parameters, adiabatic
compressibility (β), absorption coefficient (α/f2), relaxation time (τ),
intermolecular free length (Lf), free volume (Vf) and internal pressure (πi)
explained the deviation from ideality based on the strength of interaction38-45.
Moore and Fort46 measured the ultrasonic velocity, density and
adiabatic compressibility and other acoustical parameters for fourteen liquid
mixtures. In order to substantiate the molecular interaction between the
interacting molecules, the sign and magnitude of the excess parameters were
used. Excess parameters, regarded as more suitable parameters such as
excess ultrasonic velocity UE, excess viscosity ηE, excess compressibility βE,
excess impedance ZE, excess free length LfE and excess free volume VfE have
been calculated and employed. The observed results in the variation of the
excess thermodynamic parameters of the mixtures were used to explain the
structure-making and structure-breaking47 properties of the liquid mixtures.
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Most of the papers dealing with the excess thermodynamic functions are
based on works of Moore and Fort46.
The presence of dispersion forces makes a positive contribution to the
excess values47. Similarly, a dipole-dipole, dipole-induced dipole charge
transfer and hydrogen bonding interaction make a negative contribution by
the following excess parameters UE, ηE, βE, LfE and VfE make positive
contribution by ZE indicating the presence of a strong interaction between
components. On the other hand, the above excess parameters with negative
ZE are attributed to weak interaction. Further, the magnitudes of these excess
parameters were used to study the strength of interaction47.
1.5. INVESTIGATION OF MOLECULAR INTERACTIONS
The structure of a molecule determines its function. In turn, the
forces between the atoms determine the structure of the molecule. The
interactions between the atoms in a molecule are classified as strong or weak,
depending on whether or not the interaction can be disrupted by weak forces
like thermal motion. The primary structure of the macromolecules is made of
strong interactions such as the covalent bonds. Higher order structures like
secondary, ternary and quaternary structures are governed by weak forces
and can, therefore, be disrupted by relatively small increase in temperature or
a change of pH etc. Strong interactions are implicated mainly in the formation
of the chemical structure, and to some extent in the formation of the
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molecular structure. Weak interactions, on the other hand, not only help to
determine the three-dimensional structure but also are involved in the
interactions between different molecules. Any interaction within a molecule or
between molecules can be understood as a sum of the interactions between
pairs of atoms.
Hydrogen bonds and van der Waals’ interactions are classified as weak
forces. Van der Waals’ forces act between all atoms and ions in all solids but
the effect cannot be felt in the presence of strong interactions like covalent,
ionic or metallic bonds. Van der Waals’ forces are basically electrostatic in
nature. In that, they involve interaction between electric dipoles. There are
three components of the van der Waals’ forces namely, the permanent dipoles
in the molecule, the dipoles induced by an external electric field, and the one
induced by the London-dispersion effect. The relative contribution of each to
the total force varies and depends on the type of the molecule. The hydrogen
bonds are weaker than covalent bonds but are stronger than van der Waals’
bond48.
In general, when two liquids are mixed together the structure of each of
the two liquids is the same. The components change structurally in both
aqueous and non-aqueous solutions. The phenomenon of preferential
interaction between unlike molecules (solvation) or similar ones (association)
is observed, depending on the degree of affinity between the components.
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1.5.1. Pure liquids
According to Eyring et al49,50 molecules in a liquid state are so loosely
packed as to leave some free space in-between them. This free space and its
dependent properties are related to the molecular structure and may show
some interesting features about the interaction, which may occur when two
or more organic liquids are mixed. A sound wave is regarded as travelling
with gas kinetic velocity through space and infinite velocity through rest of
the path. A good deal of work has been reported50-55 on the sound velocity and
adiabatic compressibility in pure liquids and binary liquid-liquid mixtures.
Chennarayappa et al56 have analysed in terms of the structure-
making and structure-breaking effects of the components and the influence of
alcohol chain length. Isentropic compressibilities have extensive applications
in characterizing aspects of the physico-chemical behaviour of liquid
mixtures, such as molecular association, dissociation and complex formation.
Krishnamurthy and Subba Rao57, Prakash et al58, Dhanalakshmi et al59 and
many others have carried out ultrasonic studies of aqueous and non-aqueous
solutions.
1.5.2. Binary liquid system
Extensive investigations have been carried out on intermolecular
interactions in both binary and ternary liquid systems, using various
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methods like infrared, nuclear magnetic resonance, Raman method, magnetic
susceptibility and ultrasonic methods60-62. Measurement of ultrasonic velocity
and other acoustical properties can be related to physico-chemical behaviour
and molecular interactions in a number of binary systems63-65. Nomoto29
made successful attempts to evaluate sound velocity in binary liquid
mixtures. Prakash et al has carried out theoretical evaluation of ultrasonic
velocity and its correlation to molecular association in binary liquid
mixtures66. Seghal and Porter studied the non-linear parameter for alcohol-
water mixtures and based on this parameter, they have discussed the
intermolecular interactions67. Anwar Ali and co-workers carried out
investigations on the interactions of ion-solvent system by ultrasonic method.
For example, they measured ultrasonic velocity of sodium chloride in aqueous
dimethylformamide mixtures and explained the results on the basis of solute-
solvent, ion-solvent molecular interactions and the arrangement of ions in the
solution68. The ultrasonic studies of binary liquid mixtures of methanol,
acetone with cinnamaldehyde as a function of concentration were studied by
Tabhane et al69. Kannappan and Jaya Santhi70 carried out investigation on
the interactions of induced dipole-dipole interactions and intermolecular
interactions71 in binary systems.
1.5.3. Ternary liquid systems
Ultrasonic velocity in liquids has been an experimental tool for gaining
insight into the nature of the liquid state. Literature survey shows that
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various acoustical and thermodynamic parameters have been extensively
used to study the molecular interactions in ternary liquid mixture. The
formation of charge transfer complexes has been established by
spectrophotometric, X-ray diffraction72-76, NMR spectroscopy77, magnetic78,
dipole moment79, IR and Raman spectra studies. Even though spectroscopic
techniques are powerful tools for investigating the nature of molecular
complexes, these methods do not give satisfactory results on stability
constants especially in the case of weak interacting systems where ultrasonic
technique is found to be the most pioneering tool. Using this technique,
stability constant was calculated by many workers80,81. Kannappan and
Hemalatha82 studied the molecular interactions of certain aromatic
compounds with 1-chlorobenzotriazole in solution.
The isentropic compressibility and its deviations in different mixtures
have been compared with Redlich-Kister theoretical equation and the results
were found to be satisfactory83-89. Presence of electrolyte and non-electrolyte
produces different types of interactions between the molecules of solute and
the solvent. The effect of addition of an electrolyte on the formation of charge
transfer complexes of benzyl chloride and bromobenzene with o-cresol in an
inert non-polar solvent was studied using dielectric technique90-93. The
complex has been interpreted in terms of dipole moment, interaction
dielectric constant and interaction molar polarization94-96.
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1.5.4. Polymer systems
Polymer blends are physical mixtures of two structurally different
polymers that interact through weak secondary forces with no covalent
bonds. The choice of a suitable solvent for a given polymer plays an important
role in deciding the end use. This depends on the nature of interaction
between the polymer and the solvent97. Solvents can form secondary bonds
with the polymer chains, can penetrate, replace the interchain secondary
bonds and thereby pull apart and dissolve linear and branched polymers98. It
was stated by Napper99 that the high molecular weight polymer, in general, do
not participate from solution in moderately poor solvent, in the same manner
as that single electrolytes do. Recently, Kannappan and others have used
ultrasonic velocity measurements to determine glass transition temperatures
of polymers100.
1.5.5. Soaps and detergents
Ultrasonic measurements provide interesting information on the
specificity of the ion-solvent interaction related to the structure of solute and
on the reciprocal effects that arise in the solvents. However, ultrasonic
studies on soaps and detergents have not drawn adequate attention to give
more information on the soap-solvent interaction114. A number of workers101-
104 used ultrasonic measurements for the determination of ion-solvent
interaction and the results were found to be in good agreement with those
computed by other techniques like NMR2, IR105,106 and Raman4 studies.
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Mehrotra et al studied different types of soaps like yttrium
soap107, didymium soap108, lanthanum soap109, terbium soap110 and thorium
soap111 solutions. They evaluated the Critical Micelle Concentration (CMC) of
soaps and the types of interactions present in these soap solutions80,81,112.
1.6. CHARGE TRANSFER COMPLEXES
The term ‘charge transfer’ has a wide common usage to describe the
weak interactions between electron donors and electron acceptors. This
terminology is retained in the present work although it must be emphasized
that the term cannot be taken to imply that transfer of charge is the major
mode of binding in these cases. In this type of complexes, a pair of molecules
known as electron donor and electron acceptor is involved. These charge
transfer complexes have unique absorption bands in the ultraviolet-visible
region.
The compositions of donor-acceptor complexes could not be isolated at
ordinary temperatures in pure state since they are mostly unstable. But they
exist only in solutions in equilibrium with their components. The rates of
formation of complexes in solution are generally so rapid that kinetic studies
of the reactions cannot be made, at least by ordinary procedures. The heats of
interactions are generally small that the forces of coordination are much
feebler than those established in the formation of covalent bonds113. That is,
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the degree to which electron transfer from the donor component to the
acceptor component takes place is much less than that ordinarily occurs
when new compounds are formed114. Charge transfer forces are relatively of
long-range type compared to the chemical forces115. Thus, typical distances
between molecules in these complexes are 3.2 to 3.4 Ao, whereas chemical
bond lengths are less than 1.5 Ao.
1.6.1. Types of donors
The donor components are grouped into two categories. They are
π-donors and n-donors.
ππππ−−−−donors
These types of donors include alkenes, alkynes, aromatic hydrocarbons
and their substitution products. These adducts which they form are called
π-complexes116. Here the electron transfer takes place when a π-donor
coordinates with an acceptor. The term ‘outer complex’ has also been used114
in describing adducts of this kind to emphasize that the acceptor does not
make deep penetration into the π−orbital.
n-donors
These donors include a large group of substances in which there are
non-bonded electrons (lone pairs) available for coordination. Alcohols, organic
iodides and nitrogen bases are examples for these.
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34
1.6.2. Types of acceptors
In the similar way, acceptors are also grouped into two categories. They
are inorganic acceptors, π-acids and other organic acceptors.
Inorganic acceptors
Complexes of a wide variety of inorganic acceptors have been
reported117. Some of this type of acceptors are chlorine, bromine, iodine,
iodine monochloride, oxygen, salts of copper (I), silver (I) & mercury (II),
aluminium bromide and hydrogen halides.
ππππ−−−−Acids and other organic acceptors
A variety of organic compounds which function as dienophiles in the
Diels-Alder reaction, such as ethylenes with highly electronegative
substituents, chloranil, tetracyanoethylene, polynitro aliphatic, polynitro
aromatic substances, tetranitromethane in very dilute solution, nitrobenzene,
2,4,7-trinitroflurenone and 1,3,5-tricyanobenzene are some of the acceptors.
1.6.3. Types of charge transfer complexes
Charge transfer complexes may be classified according to the types of
interacting orbitals118.
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π-donors which supply electrons and π-acceptors in which it is a
π-orbital which accepts the bonding electron, and it is then delocalized over
the orbitals of adduct. The charge transfer complexes of this type are usually
strong complexes.
Complexes are formed between σ-donors and σ-acceptors in which the
bonding involves the σ−orbitals of the reactants. This type of complexes is
relatively weak.
n-donors, where the locus of the bonding electron tends to be localized
within the reactant molecule. Tertiary nitrogen is an example of this type. On
this basis, there are six types of charge transfer complexes. They are π−π, π−σ,
σ−π, n-π, n-σ and σ-σ type of complexes.
1.6.4. Methods to determine the stability of complexes
A number of experimental procedures have been adopted in
investigating equilibria established between donor-acceptor complexes and
the components in solution. They are discussed below.
Solubility method
Equilibrium constants for the formation of complexes of a number of
aromatic substances (donors) with silver ion (acceptor) in aqueous solution
have been evaluated from the results of solubility studies119. It is not possible
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36
to vary the activity or concentration of the saturating substance when it is a
liquid or a solid. Thus, when this procedure is used, there is uncertainty as
regards the number of donor molecules which are incorporated in the
complex. The uncertainty does not apply when a gaseous solution is used
since the pressure of the gaseous component and hence, its concentration in
solution can be varied. The evaluation of equilibrium constants for the
interaction of silver ion with olefins by gas chromatography is an interesting
adaptation of the gas solubility for investigating complex stabilities120,121.
Distribution measurements
This method has proved convenient in making quantitative studies of
certain types of donor-acceptor complexes. It involves measurement of
distribution of one component, usually the donor, between a liquid phase in
which only that component is appreciably soluble and a liquid phase which
contains both the donor and the acceptor and all of the complex. This is the
procedure, which has been used by Winstein and Lucas122 in investigating
the coordination of silver ion with unsaturated compounds in aqueous
medium. This method permits variation in the concentrations of both the free
donor and free acceptor. Procedures of this kind can, therefore, be applied in
establishing the true formulae of the complexes.
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37
Spectrophotometric methods
Benesi and Hildebrand123 have developed spectrophotometric method of
determination of the equilibrium constant K and the molar extinction
coefficient (absorptivity) εDA, (usually at the maximum for the charge transfer
band) of a donor-acceptor complex (DA) in solution. This along with
Mulliken’s114,124 formulation of these complexes as of the charge transfer type
has opened the floodgate to research in this area.
For a 1:1 complex formed according to the reaction,
D + A D A
the equilibrium constant, often referred to as the association constant
or stability constant is given as
K = CDA/CD CA -------------- (1.1)
Where, CDA, CD and CA are the equilibrium concentrations of DA (donor-
acceptor complex), D (donor) and A (acceptor) respectively.
The absorption spectrum of a charge transfer complex is markedly
different from the individual spectrum of the free donor and the acceptor.
This makes it possible to determine the equilibrium constant of complexes in
solution using spectroscopic methods. The optical densities (absorbances) d,
at the complex absorption maximum are measured for a series of solutions of
varying concentrations of donor, in which the donor is present in large excess
compared to the acceptor. Generally, the measurements are made against
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38
blanks, which are identical with the reaction mixtures except that they
contain no acceptor. Under this condition, the equation (1.1) reduces to
K = CDA/(CAo - CDA
o)CDo ---------------- (1.2)
where CAo and CD
o indicate the sum of the concentrations of the free and
complexed A and D.
In the simple case, in which only the complex absorbs significantly at
the wavelength of the measurements, the optical densities (d) are related to
the concentration of complex and the unit cell path length by the equation
d = εDA CDA -------------- (1.3)
Stipulating the condition that CDo >> CA
o and neither A nor D absorbs
in the region of the charge transfer band, the equation (1.3) changes to the
form
CAo/d = 1/KεDA CD
o + εDA -------------- (1.4)
The equation (1.4) is generally called as Benesi-Hildebrand equation. In the
charge transfer spectra of donor-acceptor complexes, Mulliken noted that
increase in stability constant value which normally results when donor
ionization potentials decrease should be accompanied by an increase in the
dipole moment and in the oscillator strength of the charge transfer transition.
A spectrophotometric study of the donor-acceptor system according to the
method of Benesi and Hildebrand leads to the conclusion that a complex with
K = 0 and εDA = ∞ is formed. Three different cases in which charge transfer
absorption results (a) solely from photo-excitation of complexes, (b) partly
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39
from photo-excitation of complexes and partly from contact charge transfer
and (c) entirely from contact charge transfer. Regardless of the relative
contribution of complex absorption and contact charge transfer absorption to
the measured optical densities, the ratios of the intercepts and slopes of these
plots should provide stability constant values which are the sums of the
equilibrium constants for all complexes in solution.
Ketelaar125 has modified the Benesi-Hildebrand equation wherein there
is no precondition regarding the absorbances of the acceptor and donor at the
wavelength of the measurement.
CAo/(d-dA) = 1/KεDA CD
o + 1/(εDA-εA) -------------- (1.5)
The Benesi-Hildebrand method requires an extrapolation to high
concentration region. As an alternative, Scott126 has suggested a
rearrangement of the expression which requires an extrapolation to the low
concentration region.
Foster-Hammick and Wardley127 have suggested the following equation
for a 1:1 complex
d/CDo = - Kd + KCA
o εDA ------------- (1.6)
According to this equation, a plot of (d/CDo)n against ‘d’ should be linear if the
complex is of stoichiometry n:1 which results from the equilibrium
nD + A ADn ---------- (1.7)
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40
A special feature of this method is to ensure the absence of higher order
complexes under the concentration conditions usually applied for 1:1
complexes. The Rose-Drago equation128
K-1 = d/εDA - CAo – CD
o + CAo CD
o εDA/d ---------- (1.8)
can be applied to any donor-acceptor systems that absorb in the visible or
ultraviolet region provided a 1:1 complex is formed and the donor does not
absorb in the relevant region of the study. Thus, this method can be used as
a general method to determine the equilibrium constant. Using the
experimental observations and choosing εDA randomly, K-1 is determined for
each value of εDA. The point of intersection of the curves drawn from K-1 and
εDA gives K-1. But the selection of εDA values at random, and that too for each
set of experimental data, renders this graphical method laborious and
sometimes more difficult to apply. In many cases, R-D plots show a wide
scatter in the values of K and εDA evaluated.
Person129 is of the opinion that the equimolar method of determining
the equilibrium constant should preferably be used since the errors involved
in the evaluation of K and εDA by this method are minimal. This condition
further favours the formation of 1:1 complexes.
Other methods
Equilibrium constants for the interaction can be calculated on the basis
of the changes in rate constants for the slow reactions113, which take place
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41
when the reactant concentrations are varied. Maxima or minima are observed
in plots of physical properties vs compositions of donor and acceptor
mixtures. Thus, freezing point-composition diagrams are commonly used as
bases for establishing the formulae of the complexes113 from the locations of
these maxima and minima. The physical property such as surface tension130
is determined as a function of component composition. A procedure for the
evaluation of enthalpies of interaction, which is based on the results of
cryoscopic measurements131 has also been suggested. If the donor, the
acceptor, or the complex is an ion, the complex formation constant may be
evaluated by the use of appropriate electrochemical cells132,133. The
conductometric method has also been used in determining equilibrium
constants for formation of σ complexes, ArH2+F- and in solutions of
polymethylbenzenes in hydrogen fluoride134.
1.6.5. Factors affecting equilibrium constant
Solvent effect
A polar medium facilitates formation of charge transfer complexes.
However, a strong charge transfer complex in a solvent of high dielectric
strength is likely to dissociate and become ionized118. But, majority of organic
molecular complexes are formed from neutral donors and acceptors without
appreciable changes in polarization of the components. When such complexes
are produced in solution, the interacting substances must be subjected to
some desolvation. Overall, the complex is less solvated than its free
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42
components. When a saturated hydrocarbon solvent is replaced by a
substance which itself can serve as a donor or an acceptor, the complex
generally becomes more dissociated. Studies show that iodine-naphthalene
complex decreases in stability as the solvent varies in the order n-heptane >
cyclohexane > carbon tetrachloride > n-hexane > chloroform135.
Temperature effect
The association constant of the complex decreases with increase in
temperature as the complexation equilibrium is accompanied by evolution of
heat. The effect is due to the thermal motion disorienting the partners of the
complex118.
Acceptor effect
It is difficult to make an extensive comparison of acceptor strengths
because of wide variations in solvents and temperatures which have been
used for complex formation. Generally, the acceptor strengths of organic
substances are enhanced by substituents, which are electron-withdrawing
and diminished by substituents which are electron-releasing in character.
Donor effect
Comparison of donor strengths is very complicated because of its wide
variations with respect to acceptors and solvents. The donor strength of
organic compounds generally decreases in the following order:
alkenes < mono substituted ring compounds < multi ring donors
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43
1.6.6. Applications of charge transfer complexes
Purification and separation of organic compounds
A number of methods of purification of organic substances have been
devised which are based on the differences in the capacities of the
components of a mixture to interact with a particular donor and acceptor.
Unsaturated substances are sometimes separated from other materials
through complex formation with silver nitrate136.
Optical resolution
A variety of racemates have been resolved through the formation of
complexes with optically active complexing agents. With 1-phenyl-2-
aminopropane as the active amine in the complexing agent, a partial
resolution of cis-trans-1, 5-cyclooctadiene has been accomplished137. The
latter has been completely resolved using the platinum complex prepared
from active α-methylbenzylamine138.
Analytical procedures
Certain useful procedures for identifying an organic compound have
been described which are based on the observation of some characteristic
physical property (melting point, colour, etc.) of a molecular complex derived
from the unknown. The Kofler139 microscopic technique is well suited for the
identification of compounds which are available in very limited quantity.
Other analytical procedures are based on spectrophotometric studies of
complexes.
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44
The Z value as a measure of solvent polarity
Charge transfer transition energy of the complex in a particular solvent,
designated as Z, be adopted as an empirical measure of solvent polarity140-142.
The Z value increases as the capacity of the medium to provide for ionization
increases.
Applications in biological systems
As noted by Kosower143 certain of many intermolecular interactions
which occur in biological systems may be of the type which lead to the
formation of complexes which can undergo charge transfer transition. Donor-
acceptor complexes are considered to have important functions in promoting
energy transformations in processes such as photosynthesis144,145 and
muscle-contraction146 as presented by Kearns and Calvin147. A three-
component complex of carotene (donor-carotene-acceptor) has also been
discussed as a possible medium for donor-acceptor exchanges in
photosynthesis148,149.
The relationship of complexes to reaction mechanism
There are some reactions in solutions in which catalytic action takes
place through complex formation or in which two or more of the reactants
undergo donor-acceptor interaction to form complexes which may or may not
be true reaction intermediates. Many of the reported effects of changes in
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45
medium on reactivity can be ascribed to difference in the capacities of the
various solvents to form complexes with one or more reactants somewhere
along the reaction coordinates150.
Nucleophilic substitution reactions
An interesting case of catalysis through complex formation in a
nucleophilic substitution reaction has been described by Colter and Wang151.
The rate of acetolysis of 2,4,7-trinitro-9-fluorenyl-p-toluenesulfonate is
enhanced by hexamethylbenzene, phenanthrene and anthracene.
Presumably, these donors interact more strongly with the electron deficient
activated complex of the trinitrofluorene derivative than with acceptor in the
ground state. Hexamethylbenzene, which is a poor donor for steric reasons,
does not increase the acetolysis rate.
Electrophilic aromatic substitutions and related reactions
Aryl ethers undergo electrophilic substitution reactions with the
halogens and the mechanism involves the formation of transient charge
transfer complexes between the aromatic molecules and halogens152-156.
Complexes are generally considered to play an important part in Friedel-
Crafts reactions. H.C. Brown et al157 discussed the role of reaction
intermediates of adducts of the organic halide and the catalyst and also of the
aromatic reactant and the attacking electrophile. In some instances, the
complex itself serves as the electrophilic reagent. This seems to be the case
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46
for the alkylation of aromatic substances with 3,4-dichlorobenzyl chloride in
nitrobenzene with aluminium chloride as the catalyst158.
Reactions with radical intermediates
Aromatic π-complexes in which the acceptors are themselves radicals
have been proposed as intermediates in free radical reactions. The reaction of
a phenyl radical with toluene in solution at room temperature to form mixture
of methyldiphenyls proceeds by way of a π-complex of phenyl radical and
toluene159.
The Diels-Alder reaction
The total (free and complexed) reactant concentrations for the reaction
of a diene such as 9,10-dimethylanthracene with maleic anhydride drops as
the dienophile concentration of the medium is increased. This can be
explained on the assumption that either a complex which is in equilibrium
with the reactants is a direct precursor of the product or alternately that
formation of the complex serves only to reduce the concentrations of the free
components which are the actual participants in the slow step160.
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47
Polymerization processes
Under certain conditions, silver salts function as catalysts for polymerization
of olefins and it has been suggested that complexes play a vital role as
reaction intermediates161.
Other types of reactions
A solution of stannous chloride and chloroplatinic acid in methanol
constitutes a homogenous catalytic medium for the hydrogenation of ethylene
and acetylene162. Stannous chloride also induces the formation of Zeise’s salt
from K2PtCl4 and ethylene in 1.5 M hydrochloric acid. It is presumed that the
catalytic activity of the tin-platinum salt mixture is related to the formation of
a platinum-olefin complex.
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48
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1, 3(9), 1990, 163.
110. Mehrotra, K.N. and Neeraja Sharma., Acoust. Lett., 18(9), 1995, 167.
111. Mehrotra, K.N. and Gahlaut, A.S. and Meera Sharma., Acoust. Lett., 12(6),
1988, 107.
112. Mahendran, S., Ph.D. Thesis, University of Madras, 2002.
113. Andrews, L.J. and Keefer, R.M., Molecular Complexes in organic Chemistry
Holden-Day, Inc., 1964.
114. Mulliken, R.S., J. Phys. Chem., 56, 1952, 801.
115. Slifkin, M.A., Charge Transfer Interaction of Biomolecules, Academic Press,
London, New York, 1971.
116. Dewar. M.J.S., J. Chem. Soc., 1946,406.
117. Andrews, L.J. and Keefer, R.M., Advances in Inorganic Chemistry and
Radiochemistry, Vol. 3, Academic Press, Inc., New York, 1961, 91.
Page 54
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118. Cissy Johnson, Hendrik Keyzer, Joseph Molnar, Gutmann Gutmann and Felix
Gutmann, Charge Transfer Complexes in Biological Systems, Marcel Dekker,
1997.
119. Andrews, L.J. and Keefer, R.M., J. Am. Chem. Soc., 71, 1949, 3644;
72, 1950, 3113, 5034.
120. Muhs, M.A. and Weiss, F.T., J. Am. Chem. Soc., 84, 1962, 4697.
121. Gil-Av, E. and Herling, J., J. Phys. Chem., 66, 1962, 1208.
122. Winstein, S. and Lucas, H. J., J. Am. Chem. Soc., 60, 1938, 836.
123. Benesi, H.A. and Hildebrand, J.H., J. Am. Chem. Soc., 71, 1949, 2703.
124. Mulliken, R.S., J. Am. Chem. Soc., 74, 1952, 811.
125. Ketelaar, J.A.A., Van de Stolpe, C., Goudsmit, A. and Dzcubas, W., Recl. Trav.
Chim. Pays-Bas Belg., 71, 1952,1104.
126. Scott, R.L., Recl. Trav. Chim. Pays-Bas Belg. 75, 1956, 787.
127. Foster, R., Hammick, Le. and Wardley, A.A., J. Chem. Soc., 1953, 3817.
128. Rose, N.J. and Drago, R.S., J. Am. Chem. Soc., 81, 1959, 6138.
129. Person, W.B., J. Am. Chem. Soc., 87, 1965, 167.
130. Cagnoli, N., Ann. Chim. (Rome), 48, 1958, 839, 1122.
131. De Maine, P.A.D., Can. J. Chem., 38, 1960, 1635.
132. Rossotti, F.J.C. and Rossotti, H., The Determination of stability constants, Mc
Graw-Hill, New York, 1961.
133. Cabani,S. and Scrocco, E., J. Inorg. and Nuclear Chem., 8, 1958, 332.
134. Kilpatrik, M. and Luborsky, F.E., J. Am. Chem. Soc., 75, 1953, 577.
135. De Maine, P.A.D. and Peone, J. Jr., J. Mol. Spectr., 4, 1960, 262.
136. Nichols, P.L., J. Am. Chem. Soc., 74, 1952,1091.
137. Cope, A.C., Ganellin, C.R. and Johnson, H.W., and Jr., J. Am. Chem. Soc., 84,
1962, 3191.
Page 55
55
138. Cope, A.C., Ganellin, C.R. and Johnson, H.W., Jr., Van Auken, T.V. and
Winkler, H.J.S., ibid., 85,1963, 3276.
139. Kofler, L. and Kofler, A., Mikromethoden zur Kennzeichnung Organische.
Stoffe und Stoffegemische, Innsbruk, Univ. Wagner, 1948.
140. Kosower, E.M. and Klinedinst, E.P., J. Am. Chem. Soc., 78, 1956, 3493.
141. Kosower, E.M. ibid., 78, 1956, 5700.
142. Kosower, E.M. ibid., 80, 1958, 3253.
143. Kosower, E.M., J. Am. Chem. Soc., 78, 1956, 3497.
144. Calvin, M., Rev. Modern Physics, 31, 1949, 147.
145. Arnold, W. and Clayton, R.K., Proc. Nat’l. Acad.Sci. U.S., 46, 1960, 769.
146. Szent, A., Gyorgyi, Radiation Res. Suppl., 2, 1960, 4.
147. Kearns, D.R. and Calvin, M., J. Am. Chem. Soc., 83,1961, 2110.
148. Platt. J.R., Science, 129, 1959, 372.
149. Rosenberg, B., J. Chem. Phys., 34, 1961, 812.
150. Leffler, J.E. and Grunwald, E., Rates and Equilibria of Organic Reactions, John
Wiley & Sons, Inc., Newyork, 1963, 50.
151. Cotler, A.K. and Wang, S.S., J. Am. Chem. Soc., 85, 1963, 114.
152. De la mare, P.B.D. and Ridd, J.H., ‘Aromatic Substitution: Nitration and
Halogenation’, Baterworth’s Scientific Publications, London, 1959.
153. Berliner, E., Prog. Phys. Org. Chem., 2, 1964, 253.
154. Stock, L.M. and Brown, H.C., Advan. Phys. Org. Chem., 1, 1963, 35.
155. Norman, R.O.C and Taylor, R., ‘Electrophilic substitutions in Benzenoid
Compounds,’ American Elsevier Publishing Co., New York, 1965.
156. Marino, G., Tetrahedron, 21, 1965, 843.
157. Brown, H.C., Pearsall. H.W., Eddy, L.P., Wallace, W.J., Grayson, M. and
Nelson, K.L., Ind. Eng. Chem., 45, 1953,1462.
Page 56
56
158. Brown, H.C. and Grayson, M., J. Am. Chem. Soc., 75, 1953, 6285.
159. Jacquiss, M.T. and Szwarc, M., Nature, 170, 1952, 312.
160. Andrews, L.J. and Keefer, R.M., ibid., 77, 1955, 6284.
161. Salomon, G., Rec. Trav. Chim., 68,1949, 903.
162. Cramer, R.D., Jenner, E.L., Lindesy, R.V., Jr. and Stolberg, U.G., J. Am. Chem.
Soc., 85, 1963, 1691.
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58
CHAPTER - 2
EXPERIMENTAL METHODS
In this chapter, the materials employed in the present investigation,
their purification techniques and details of the instruments used are outlined
briefly.
2.1. EXPERIMENTAL TECHNIQUES & INSTRUMENTATION
2.1.1. Ultrasonic Velocity Measurement for Liquids
For the measurement of ultrasonic velocity, the following techniques
are usually employed. They are: (a) Pulse method, (b) Interferometer method
and (c) Continuous wave method.
Ultrasonic Interferometer
The ultrasonic interferometer is a simple and direct device to determine
the ultrasonic velocity in pure liquids and liquid mixtures1 with high degree of
accuracy. It is known for its easy operation and reliability. Measurement of
ultrasonic velocity is based on accurate determination of the wavelength of
sound waves in the medium.
Working Principle
Ultrasonic waves of known frequency (ν) are produced by a quartz
crystal fixed at the bottom of a diode walled cell. The experimental liquid is
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59
taken in this cell and ultrasonic waves are passed into the medium. A
movable metallic plate kept parallel to the quartz crystal reflects the waves. A
fine micrometer screw is provided to raise or lower the reflector plate. When
the distance between the metal reflector and the quartz crystal equals the
whole multiples of wavelength, stationary waves are formed in the medium.
The acoustic resonance gives rise to electric reaction on the generator driving
the quartz crystal and maximum anode current flows through the generator.
When the distance is increased or decreased exactly by one half of the
wavelength (λ/2) or integral multiple of it, anode current becomes maximum
again. Using the micrometer screw attached to the reflector, the distance
moved can be measured to an accuracy of 0.001 mm (Fig. 2.1). From the
measured value of wavelength (λ), the ultrasonic velocity (U) can be calculated
using the relation,
U = νλ ms-1 -------------- (2.1)
where ‘ν’ is the frequency of the generator which is used to excite the crystal
whose value is 2 x 106 hertz.
Description
The ultrasonic interferometer consists of two important parts.
They are:
1. The high frequency generator and
2. The measuring cell
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61
The high frequency generator is designed to excite the quartz crystal
fixed at the bottom of the measuring cell, at its resonant frequency to
generate ultrasonic waves in the experimental solution filled in the measuring
cell. A fine micrometer screw of least count 0.001 mm is fixed at the top to
observe the changes in the current flow. Two knobs, namely, adjust and gain,
are provided on the panel of the high frequency generator to pass the current
through micro-ammeter and the changes in the anode current can be
measured from the micro-ammeter.
The measuring cell is a specially designed double walled cylinder for
maintaining the temperature of the experimental liquids constant throughout
the experiment. By raising or lowering the reflector plate using micrometer,
the effective length of the liquid column is varied. The micro-ammeter shows
maxima and minima for increase or decrease of distance between the plate
and the crystal. The distance of separation between a successive maxima and
minima in the anode current is equal to half the wavelength of ultrasonic
wave in pure liquid or liquid mixture. By noting the initial and final position
of the micrometer for one complete oscillation (maxima and minima), one can
determine the distance (d) moved by the parallel reflector. The number of
successive maxima and minima (n) are counted as a distance. The distance
moved by the micrometer screw gives the wavelength as
λ = 2d/n ------------------- (2.2)
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62
Using the above relation, the ultrasonic velocity of the liquids and liquid
mixtures can be calculated using the relation 2.1. The accuracy in the
measurement of ultrasonic velocity is ± 0.1 ms-1. The instrument model F-81
was supplied by M/s Mittal Enterprises, New Delhi.
There are facilities to measure the ultrasonic velocities at different
temperatures of the liquid. For this, the measuring cell is specially designed
with a double walled cylinder provided with an inlet and outlet for the
circulation of water, to maintain the temperature of the experimental liquids
constant throughout the experiment. By using Juloba thermostat (accuracy
± 0.1 K), water is circulated at any desired constant temperature through the
outer wall of the cell.
2.1.2. Density Measurements
The density of the pure liquids, liquid mixtures, detergents, dyes and
enzyme solutions can be determined by relative measurement method.
Specific gravity bottle was standardized using double distilled water. The
temperature is maintained constant by immersing the bottle in Juloba
thermostat for 15 minutes. The density of liquid and liquid mixtures can be
calculated using the formula
ρ = (Mρw/Mw ) ----------------- (2.3)
Where M is the mass of the liquid or liquid mixtures
(accuracy ± 0.001 g), Mw is the mass of water and ρw is the density of water at
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63
the experimental temperature. Density of water at different temperatures is
taken from the literature2.
2.1.3. Viscosity Measurements
The capillarity viscometric method, which is based on Poiseuille’s law,
is commonly employed for the measurement of viscosity. In the present work,
Ostwald viscometer is employed. The viscometer is filled with the
experimental solution. The flow time at different temperatures is measured by
placing the viscometer in a thermo-stated water bath with an accuracy of
± 0.1 K with temperature set at required value. An electronic stop watch was
employed to measure the time of flow.
The absolute value of coefficient of viscosity of the solution (η) can be
calculated using the formula
η = (ρsts/ρwtw ) ηw ---------------- (2.4)
where η = ρs – density of the solution; ts – flow rate of the solution;
ρw – density of water; tw – flow rate of water and ηw – coefficient of viscosity of
water. The accuracy of viscosity in this method is
± 0.001 Nsm-2.
The following precautions were taken for getting accurate and reproducible
results.
• Care was taken while mounting the viscometer to see that the capillary
is always held in vertical position.
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64
• All measurements are made at a constant temperature with an
accuracy of ± 0.1 K, since viscosity is highly temperature sensitive. The
viscosity of water at a given temperature has been taken from
literature2.
• The solutions are equilibrated with thermostat for 15 minutes, so that
the experimental solution attains the same temperature of the
thermostat.
2.1.4. Thermostat
The temperature of the solution under study is maintained constant
using the electronic Juloba thermostat. This thermostat is equipped with a
heater, a stirrer, a thermometer and a regulator. The temperature was
maintained at 303 K for all the systems with an accuracy of ± 0.1 K.
2.2. MATERIALS
2.2.1. Solids
Iodine (Merck GR grade) was purified by sublimation. The hydrocarbons
naphthalene, biphenyl and anthracene were AnalaR grade samples and were
used as such.
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65
2.2.2. Water
Water used in the present study is triple distilled water of high purity.
It is obtained by redistilling the double distilled water over alkaline potassium
permanganate in an all glass quick-fit distillation set up.
2.2.3. Solvents and Liquids
The liquids used in the present investigation along with their boiling
points are given in Table 2.1. All the liquids mentioned here are AnalaR grade
samples and they are purified by usual
methods3,4 before use. The boiling points of these liquids agreed well with the
literature values indicating that the liquids used in the present studies are of
high purity.
Solutions of iodine and iodine monochloride in different solvents are
prepared as follows. A stock solution of 0.1 M was prepared by dissolving
accurately weighed solid donor in their respective solvents. This stock
solution was diluted to get the required concentration. Equimolar
concentrations of donor and acceptor were mixed to obtain mixtures of
desired concentration.
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66
Table 2.1. Physical constants of certain compounds
S. No. Compound Boiling
Point (oC)
1 Water 100
2 Ethanol 78.5
3 Bromobenzene 156.2
4 Chlorobenzene 132
5 Iodine monochloride 97
6 o-Cresol 464
7 p-Cresol 474.9
8 m-Cresol 202.5
9 Phenol 180
10 Carvacrol 237
11 Dichloromethane 40
12 Chloroform 62
13 Carbon tetrachloride 76.5
14 n-Hexane 68.7
15 Mesitylene 164.7
16 p-Xylene 137.5
17 m-Xylene 139.3
18 o-Xylene 138.5
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67
19 Benzene 80.1
20 Toluene 110.6
21 Diphenyl ether 259
22 4-Chloroanisole 198
23 Anisole 154
24 1,4-Dioxane 101
Page 68
68
REFERENCES
1. Gooberman, G.L., Ultrasonics Theory and Applications, The English
Univ. Press, London, 1968.
2. Lide, D.R., CRC Handbook of Chemistry and Physics, 81st Edn., CRC
Press, Inc., 2001.
3. Vogel, A.L., Textbook of Practical Organic Chemistry, 5th
Edn., John
Wiley, New York, 1989.
4. Riddick, J.A., Bunger, W.B. and Sakano, T.K., Techniques in Chemistry,
Vol. II, Organic Solvents, 4th
Edn., John Wiley, New York, 1990..
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70
CHAPTER - 3
THEORY AND CALCULATIONS
This chapter contains the formulae employed in the calculation of
various acoustical parameters. The theoretical background in computing
acoustical, thermodynamic, molecular and surface properties is given here.
3.1. ULTRASONIC VELOCITY (U)
Numerous methods have been reported in the literature for computing
ultrasonic velocity1-3. The ultrasonic velocity determined by interferometer
method is considered as more reliable and precise. In this instrument, we can
determine the wavelength (λ) of the ultrasonic wave in liquid and liquid
mixtures. The expression used to determine the ultrasonic velocity is
U = νλ ms-1 --------------- (3.1)
Where, ‘ν’ is the frequency of the generator which is used to excite the crystal.
In the present investigation, a constant frequency (2 MHz) interferometer was
employed and hence ‘ν’ value is 2 x 106 hertz.
3.2. ADIABATIC COMPRESSIBILITY (κκκκ)
Adiabatic compressibility is a measure of intermolecular association or
dissociation or repulsion. Singh and Kalsh4 showed that the adiabatic
compressibility should be independent of temperature and pressure for
unassociated and weakly associated molecules. It also determines the
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71
orientation of the solvent molecules around the liquid molecules. The
structural arrangement of the molecule affects the adiabatic compressibility.
It can be calculated using the equation5
κ = 1/U2ρ kg-1 ms-2 ------------- (3.2)
Where, U is the ultrasonic velocity and ρ is the density of the solution.
3.3. ABSORPTION COEFFICIENT (αααα/f2)
The absorption coefficient also called attenuation coefficient, is
characteristic of the medium and it also depends on the external conditions
like temperature, pressure and the frequency of measurement. It is a
measure of spatial rate of decrease in the intensity level on ultrasonic waves.
Treating the propagation of sound as an adiabatic phenomenon and following
Stoke’s theory, absorption may be taken as being proportional to the viscosity
of the medium and the square of the frequency. It can be calculated from the
viscosity (η) using the relation6
(α/f2) = 3
2
3
8
Uρ
ηΠ Nps2m-1 --------------- (3.3)
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72
3.4. MOLECULAR INTERACTION PARAMETER (χχχχU)
The molecular interaction parameter can be computed using the
following formula7:
χU = 1exp
−idealU
U ------------------ (3.4)
Where, Uexp is the observed ultrasonic velocity of the experimental solution
and Uideal is the ultrasonic velocity of the ideal mixture of the components in
the solution under study.
The sign of the molecular interaction parameter predicts the strength of
the interaction between the molecules in the solution. If χU value is negative,
then the interaction will be stronger between the molecules and the
interaction will be weak if the value of χU is positive. Thus, from the value of
this parameter, we can assess intermolecular attraction.
3.5. RELAXATION TIME (ττττ)
Relaxation time and absorption coefficient are directly correlated. The
absorption of a sound wave is the result of the time lag between the passing
of the ultrasonic wave and the return of the molecules to their equilibrium
position. It is calculated using the relation8
τ = 23
4
Uρ
η s ---------------------------------------- (3.5)
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73
3.6. FREE LENGTH (Lf)
The free length is the distance between the surfaces of the neighbouring
molecules. Generally, when the ultrasonic velocity increases, the value of the
free length decreases. The decrease in intermolecular free length indicates the
interaction between the solute and solvent molecules due to which the
structural arrangement in the neighbourhood of constituent ions or
molecules gets affected considerably. The intermolecular free length has been
calculated using the following formula given by Jacobson9,10
Lf = ρU
K °A --------------------- (3.6)
Where, K is Jacobson’s constant. This constant is a temperature dependent
parameter whose value at any temperature (T) is given by (93.875 + 0.345T) x
10-8.
3.7. FREE VOLUME (Vf)
Free volume is defined as the average volume in which the centre of the
molecules can move inside the hypothetical cell due to the repulsion of
surrounding molecules. Free volume can be calculated by different methods.
Chellaiah et al11, Erying et al12, Kinacid et al13,
Mc Leod14 and Hildebrand15 have made a few approaches in calculating the
free volume. Suryanarayana and Kuppusamy16 on the basis of dimensional
analysis, obtained an expression for free volume in terms of experimentally
measurable parameters like ultrasonic velocity and viscosity and is given by
Page 74
74
Vf = [Meff U/Kη]3/2 m3 ---------------- (3.7)
Where, Meff is the effective molecular weight, which is expressed as
Meff = (X1M1 + X2M2 + X3M3). Where, X and M are the mole fraction and
molecular weight of the individual component in the mixture respectively. K is
the temperature independent constant and its value is 4.28 x 109.
3.8. INTERNAL PRESSURE (ππππi)
Internal pressure is a fundamental property of a liquid, which provides
an excellent basis for examining the solution phenomenon and studying
various properties of the liquid state. It is a measure of the change in the
internal energy of liquid or liquid mixtures, as it undergoes a very small
isothermal change. It is a measure of cohesive or binding forces between the
solute and solvent molecules.
The internal pressure16 of the liquid mixture is obtained from the
experimental values of ultrasonic velocity, density and viscosity using
πi = bRT (Kη/U)1/2 (ρ2/3/Meff)7/6 atm -------------- (3.8)
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75
3.9. COHESIVE ENERGY (CE)
The concept of molar cohesive energy has been used by several
researchers17-20 for comparing the interaction in the liquid mixtures. It is
usually given as a product of internal pressure (πi) and molar volume (Vm)
CE = πi x Vm kJmol-1 ---------------- (3.9)
A molecule containing strong polar groups exerts corresponding strong
attractive forces on its neighbours. If the intermolecular forces are small, the
cohesive energy is low and the molecules have relatively flexible chains.
3.10. ACOUSTIC IMPEDANCE (Z)
Sound travels through materials under the influence of sound
pressure. Since, molecules or atoms of a liquid are bound elastically to one
another, the excess pressure results in a wave propagating through the
liquid21. The acoustic impedance is given by the product of ultrasonic velocity
and density as shown below:
Z = U x ρ kg m-2s-1 ----------------- (3.10)
Acoustic impedance is important in the determination of acoustic
transmission and reflection at the boundary of two materials having different
acoustic impedance. It is also useful in the designing of ultrasonic
transducers and for assessing absorption of sound in a medium.
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76
3.11. AVAILABLE VOLUME (Va)
The available volume is a direct measure of compactness in the liquid
and the strength of attraction between the molecules of a liquid or a liquid
mixture. It can be calculated from Schaaf’s relation
Va = Vm (1 – U/U ∞) m3 --------------- (3.11)
Where, Vm is the molar volume which is equal to (Meff/ρ) and
U∞= 1600 ms-1
3.12. LENARD JONES POTENTIAL (LJP)
The Lenard Jones Potential is given by22
LJP ≈ 6Vm/Va -------------- (3.12)
Where, Vm represents the molar volume and Va represents the available
volume.
3.13. FREE ENERGY OF FORMATION (∆G)
The free energy of formation is calculated using the relation
∆G = - RT ln K kJmol-1 ------------- (3.13)
Where, R is the gas constant, T is the temperature in kelvin and K is the
formation constant.
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3.14. FREE ENERGY OF ACTIVATION (∆G#)
The free energy of activation is calculated by
∆G# = - KB T ln (h/τ KB T) kJmol-1 ------------- (3.14)
Where, KB is Boltzmann constant (1.3806 x 10-23 JK-1), T is the temperature,
h is Planck constant (6.626 x 10-34 Js) and τ is the relaxation time.
3.15. STABILITY CONSTANT (K)
Marwein and Bhatt23 have proposed an equation to calculate the
stability constants of donor-acceptor complexes in binary liquids, which
generally gives concentration dependent formation constant values. Recently,
we have proposed an equation to calculate the formation constant values of
the charge transfer complexes, appreciable to weak complexes and in very
dilute solutions24,25. The stability constant is calculated using the relation
K = Y/(b-y)2 dm3mol-1 ---------------- (3.15)
Where, Y = (a – k1/2b)/(k – k1/2);
k = x/y.
x = difference between Ucal and Uobs at lower concentration ‘a’,
y = difference between Ucal and Uobs at higher concentration ‘b’ and
Ucal = the ultrasonic velocity of the mixture calculated from the mole fractions
of the components using additive principle.
This equation can be used to calculate stability constant values for different
combinations of concentrations ‘a’ and ‘b’.
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78
3.16. EXCESS THERMODYNAMIC PARAMETERS
The excess thermodynamic parameters which play a major role in
understanding the nature of molecular interaction in liquid mixtures have
been studied by several workers26-28. The excess thermodynamic parameters
are defined as the difference between the experimental and ideal mixture
values. It gives a measure of the non-ideality of the system as a consequence
of associative or of other interactions29.
The excess values of the parameters have been computed from the
following expressions30:
Excess ultrasonic velocity:
UE = Uexp – (X1U1 + X2U2) ms-1 ---------------- (3.16)
Where, U1 and U2 are the ultrasonic velocities of solute and solvent and Uexp
is the ultrasonic velocity of the mixture. X1 and X2 are the mole fractions of
the solute and solvent.
Excess viscosity:
ηE = ηexp – (X1η1 + X2η2) Nsm-2 --------------- (3.17)
Where, η1 and η2 are the viscosities of solute and solvent, and ηexp is the
viscosity of the mixture.
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79
Excess adiabatic compressibility:
κE = κexp – (X1κ1 + X2κ2) kg-1ms2 ------------- (3.18)
Where, κ1 and κ2 are the adiabatic compressibility values of solute and
solvent and κ exp is the adiabatic compressibility of the mixture calculated
using the Laplace relation
κ = 1/U2 ρ.
Excess free volume:
VfE = Vf(exp) – (X1Vf1 + X2Vf2) m3 ----------------- (3.19)
Where, Vf1 and Vf2 are the free volumes of solute and solvent and Vf(exp) is the
free volume of the mixture.
Excess free length:
LfE = Lf(exp) – (X1Lf1 + X2Lf2) m -------------- (3.20)
Where, Lf1 and Lf2 are the free lengths of solute and solvent and Lf(exp) is Lf
value of the mixture.
Excess acoustic impedance:
ZE = Zexp – (X1Z1 + X2Z2) kg-2s-1 -------------- (3.21)
Where, Z1 and Z2 are the acoustic impedance values of solute and solvent and
Z(exp) is Z value of the mixture.
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80
Excess available volume:
VaE = Va(exp) – (X1Va1 + X2 Va2) m3 --------------------------- (3.22)
Where, Va1 and Va2 are the acoustic impedance values of solute and solvent
and Va (exp) is Va value of the mixture.
Forte and More31 suggested that the negative contribution to excess
value indicates strong molecular interactions due to dipole-dipole, dipole-
induced dipole, charge transfer and hydrogen bonding.
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81
REFERENCES
1. Bhatt, S.S. and Singh, D.P., Ind. J. Pure & Appl. Phys., 21, 1983, 506.
2. Marwein and Bhatt, S.N., Thermochemica Acta, 118, 1987, 277.
3. Thabane, Y.A., Mulay, V.D., Ghose, S. and Khasare, S.B., Acustica, 81C,
1993, 187.
4. Singh, D.P. and Kalsh, S.C., Acoustics Letters, 14(10), 1991, 206.
5. Rajan Dass, Prakash, K., Muhuri and Dilip K. Hazra, Acoustics Letters,
18(4), 1994, 69.
6. Hassun, S.K., British Polymer. J., 17(4), 1985, 330.
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8. Subhi Kemal Hassun, Acoustics Letters, 11(10), 1988, 195.
9. Jacobson, B., Acta Chemica Scand., 5, 1951, 1214., 6, 1952, 1485.
10. Jacobson, B., J. Chem. Phys., 20, 1952, 927.
11. Chellaiah, N. and Sebesan, R., Ind. J. Pure & Appl. Phys., 32, 1994, 315.
12. Erying, H. and Hischfelder, J. Phys. Chem., 41, 1937, 249.
13. Kinacid, J. and Erying, H., J. Chem. Phys., 6, 1938, 620.
14. Mc Leod, D.B., Trans Farad. Soc., 41, 1945, 771.
15. Hildebrand, J.H., J. Am. Chem. Soc., 71, 1949, 2703.
16. Suryanarayana, C.V. and Kuppusamy, J., J. Acoust. Soc. Ind., 4, 1976, 75.
17. Rao, A.V., Venkateswaralu, P., Raman, G.K. and Rajulu, A.V., Acta
Polym. 43, 1992, 185.
18. Aruna, P., Natarajan, S. and Suryanarayana, C.V., Ind. J. Tech., 29,
1991, 537.
19. Rajendran, V., Ind. J. Pure & Appl. Phys., 34, 1996, 52.
20. Kannappan, V. and Kothai, S., Ind. J. Pure & Appl. Phys., 40, 2002, 17.
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21. Kannappan, V. and Kothai, S., J. Acous. Sci. Ind., 29, 2001, 169.
22. Jayakumar, S., Ph.D. Thesis, University of Madras, 1999.
23. Marwein, B.L. and Bhatt, S.N., Acustica, 58, 1985, 243.
24. Kannappan, V. and Kothai, S., Advances of Ultrasonics., 2001, 124.
25. Kannappan, V. and Kothai, S., J. Pure & Applied Ultrasonics., 2002, 24.
26. Jiri Polak., Canad. J. Chem., 48, 1970, 2457.
27. Golla Narayanaswamy., Canad. J. Chem., 58, 1980, 229.
28. Prakash, O. and Darbari, S., Acoustics Letters, 12(2), 1988, 35.
29. Anwar Ali, Anil Kumar Nain, Vinod Kumar Sharma and Shakil Ahmad,
Acoustics Letters, 24(1), 2000, 9.
30. Rajaguru, P. and Jayaraj, Acoustics Letters, 13(8), 1990, 142.
31. Forte, R.J. and More, W.R., Trans. Faraday Soc., 61, 1963, 2102.
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CHAPTER – 4
ULTRASONIC INVESTIGATIONS OF MOLECULAR INTERACTIONS IN BINARY LIQUID MIXTURES
4.1. INTRODUCTION
In the recent past, ultrasonic studies on various organic liquid mixtures
have been extensively studied. There is a rapid growth in the number of
research publications in this field1-10. This is due to the fact that the optical
methods cannot detect and assess all types of interactions, especially weak
interactions in liquid mixtures. The important physico chemical properties
like adiabatic compressibility, heat capacity, coefficient of expansion and
critical temperature may be obtained from ultrasonic velocity, density and
viscosity data. The molecular interactions in pure and binary liquid mixtures
can be analysed using ultrasonic velocity measurements which are of
considerable interest for the physicists in the last few decades11-21. Excess
free length (LfE) can be used to access the molecular interactions in binary
liquids and a comparison of the sign of LfE with excess volume (VE) or with
other thermodynamic parameters has been made by several workers22-26.
4.1.1. Types of molecular interactions
There are five types of molecular interactions between the component
molecules in binary liquid mixtures. The strength of these interactions is in
the order
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85
ion-ion > ion-dipole > dipole-dipole > dipole-induced dipole >
induced dipole-induced dipole.
The factors that influence the strength of the molecular interactions are
described below:
The strength of ionic attraction depends on the charge and inter-ionic
distance. This can be obtained using Born-Lande equation
E = r
eZZ
oεΠ−+
4
2
--------------- (4.1)
The attraction of one ion by another is completely independent of direction
but sizes and charge number determine the ion-ion interaction energy. On
the contrary, ion-dipole forces may be thought as ‘directional’ in that they
result in preferred orientations of molecules. The potential energy of an ion-
dipole interaction is given by
E = 24 r
Z
o
r
ε
µ
Π
±
---------------- (4.2)
Where, ‘ ±Z ’ is the charge on the ion and ‘r’ is the distance between ion and
‘µr’ is the molecular dipole. Ion-dipole interactions are similar to ion-ion
interaction except that they are more sensitive to distance [(2
1
r) instead of (
r
1 )]
and seems to be some what weaker.
The energy of the interaction of the dipoles may be expressed as
E = 3
21
4
2
roε
µµ
Π
− ---------------- (4.3)
This energy corresponds to head to tail arrangement as shown below (Fig.4.1).
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86
Fig. 4.1. Dipole – dipole attraction
Fig. 4.2. Dipole – dipole interaction
An alternate arrangement is anti-parallel arrangement (Fig.4.2) which will be
more stable if the molecules are not too ‘fat’. At moderate temperature and in
the gas phase, there will be a tendency for internal motion to randomize the
orientation of dipoles and the energy of interaction will be considerably
reduced. However, in liquid mixtures at room temperature, the dipole-dipole
interaction energy is greater than that in gas phase containing the same
molecular components. Dipole-dipole interactions tend to be even weaker
than ion-dipole interaction and fall off more rapidly with distance (3
1
r) and
they are decreasing in character.
There may be two types of interactions in liquid mixtures containing
polar and non-polar molecules as components. They are dipole-dipole and
- + - +
+
-
-
+
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87
dipole-induced dipole interactions. The dipolar molecules disturb the electron
cloud of the non-polar molecule and this type of polarization of neutral
species will depend upon the inherent polarizability (of systems), ,α and on
the polarizing field offered by the dipole. This interaction energy is much
weaker than the energy of dipole-dipole interaction. The interaction energy is
much weaker than the energy of dipole-dipole interaction. The energy of
interaction if given by
E = 6
2
r
αµ− -------------- (4.4)
Where, ‘µ ’ is the dipole moment of inducing dipole. Since the energy varies
inversely with high power of ‘r’, they are effective only at very short distances.
Even in molecules which have no permanent dipole, instantaneous
dipoles will arise as a result of momentary imbalances in electron
distribution. These dipoles are capable of inducing dipoles in adjacent
molecules. Induced dipole-induced dipole attractions are extremely short
ranged and weak. The energy of such interactions may be expressed as
E = 6
2
r
αµ− ------------ (4.5)
Where, ‘µ ’ is the mean instantaneous dipole or
E = 6
2
4
3
r
Iα− ---------------- (4.6)
Where, ‘α ’ is the polarizability and ‘I’ is the internal energy of the species.
London forces are external short range in action (depending upon (6
1
r)) and
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88
the weakest of all attractive forces of interest to chemists and physicists. As a
result of the ‘ 2α ’ term, London force increases rapidly with molecular size or
more properly molar volume and the number of polarizable electrons.
At extremely short distances, the electronic clouds of the interacting
molecules begin to overlap and Pauli repulsion becomes extremely large. The
repulsive energy is given by
E = n
r
k+ ---------------- (4.7)
Where, ‘k’ is a constant and ‘n’ may have various values (usually ‘n’ may take
values from 5 to 10). Repulsive energies come into play only at extremely
short distances.
4.2. Results and Discussion
In this chapter, the results obtained in the ultrasonic velocity
investigations of the following six binary systems are presented and
discussed.
1. Benzene – carbon tetrachloride
2. Bromobenzene – chlorobenzene
3. Ethanol – water
4. Ethanol – p-cresol
5. Ethanol – phenol
6. Ethanol – pyridine
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89
Benzene and carbon tetrachloride are non-polar and there are only
induced dipole-induced dipole interactions in the mixture of benzene and
carbon tetrachloride. However, dipole-dipole attraction exists in
bromobenzene-chlorobenzene system. Phenols are dipolar molecules and they
are associated through hydrogen bonding which is evident from the
spectra27-30. Four binary systems are chosen such that they contain ethanol
as the common component and the second component is varied. In these four
systems, the variation in the intermolecular attraction is mainly due to the
second component. Thus, acoustical studies are made on six binary liquid
mixtures such that different types of molecular attractions could be assessed.
The acoustical parameters were calculated for benzene-carbon
tetrachloride and bromobenzene-chlorobenzene systems of various
compositions, from ultrasonic velocities, densities and viscosities at 303 K
and they are given in Tables 4.1 – 4.4. The data for the other four systems at
303 K are given in Tables 4.5 – 4.12. These data are discussed in the light of
molecular interactions between the components which exist in the six binary
liquid systems.
4.2.1. Ultrasonic Velocity (U)
The ultrasonic velocity (U) increases with increase in mole fraction of
benzene in benzene – carbon tetrachloride system but decreases with
increase in mole fraction of bromobenzene in bromobenzene – chlorobenzene
system. This suggests that there are different types of molecular interactions
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90
between the components in these binary mixtures. Fig. 4.1 contains the plots
of ultrasonic velocity vs mole fraction of the first components. The linear
variation in the ultrasonic velocity values in these systems suggests that
these systems behave almost ideally. The curve obtained in the case of
bromobenzene-chlorobenzene system is steeper than that of benzene-carbon
tetrachloride system which indicates that slightly stronger dipole-dipole
interactions exist in the former while weak induced dipole-induced dipole
interactions exist in the latter.
In the case of ethanol-water, ethanol-p-cresol, ethanol-phenol and
ethanol-pyridine systems, the ultrasonic velocity decreases with increase in
mole fraction of ethanol (Fig. 4.7). It is seen that in the case of ethanol-water
system, the ultrasonic velocity increases, reaches a maximum and then
decreases with increase in the mole fraction of ethanol. The increase in
ultrasonic velocity indicates that water molecules behave as structure breaker
for ethanol clusters. The decrease in velocity at higher mole fraction shows
that the molecules of the components are strongly attracted by hydrogen
bond. In other three systems, the extent of intermolecular hydrogen bond
between the components increases with increase in the mole fraction of the
second component.
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91
4.2.2. Adiabatic Compressibility (κκκκ)
The adiabatic compressibility (κ) values for various compositions of six
binary mixtures have been computed from the measured values of ultrasonic
velocities and densities (Tables 4.1, 4.3, 4.5, 4.7, 4.9 and 4.11). The plots of
adiabatic compressibility vs mole fraction of the first component are given in
Fig.4.2 for benzene-carbon tetrachloride and bromobenzene-chlorobenzene
systems. In both the cases the value of compressibility decreases with
increase in concentration indicating strong molecular interaction over a wide
range of concentration. Slightly steeper curve obtained in bromobenzene-
chlorobenzene system shows that the molecular attractions (dipole-dipole) in
these systems are slightly stronger than induced dipole-induced dipole
attractions in benzene-carbon tetrachloride system.
In the case of mixtures of ethanol- water, ethanol-p-cresol, ethanol-
phenol and ethanol-pyridine, the plots in Fig. 4.8 show that there is an
increase in compressibility with an increase in concentration except in
ethanol-water system. This indicates strong molecular interactions between
ethanol and molecules of other components and the intramolecular
attractions become weak among each component. A comparison of the values
of ‘κ’ in these three mixtures suggests that their compressibilities are in the
order:
Ethanol-pyridine > ethanol-p-cresol > ethanol-water > ethanol-phenol.
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92
It may be noted that in the case of ethanol-water mixture, the compressibility
decreases to a minimum value and then increases. This indicates a stronger
dipole-dipole interaction even at lower concentration and water acts as
structure breaker for ethanol.
4.2.3. Absorption coefficient (αααα/f2)
The absorption coefficient (α/f2) values in a system can be used to
ascertain the variation in intermolecular attraction and also to establish the
existence of similar types of interaction in different binary systems. In the
binary systems studied, the absorption coefficient values increase with
increase in the mole fraction of the first component in three systems namely,
bromobenzene-chlorobenzene, ethanol-water and ethanol-pyridine systems,
while it decreases in other systems (Tables 4.1, 4.3, 4.5, 4.7, 4.9 and 4.11).
This trend suggests that different types of molecular interaction exist in these
binary systems.
4.2.4. Molecular Interaction Parameter (χχχχU)
The molecular interaction parameter (χU) values are calculated and
presented in Tables 4.1, 4.3, 4.5, 4.7, 4.9 and 4.11 for the six binary systems.
These values are negative for benzene-carbon tetrachloride and
bromobenzene-chlorobenzene mixtures indicating the presence of attractive
forces. In benzene-carbon tetrachloride system, the molecular interaction
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93
parameter values are more negative. Plots of ‘χU’ vs X1 are presented in
Fig.4.3. It is interesting to note that in bromobenzene-chlorobenzene system,
molecular interaction parameter values are more negative than those for
benzene-carbon tetrachloride system. Further, the molecular interaction
parameter values are minimum at X1 = 0.4 – 0.6 suggesting that the two types
of interactions are concentration dependent and hence, the distance between
the component molecules. It may be noted that molecular interaction
parameter values are more negative for binary mixtures of bromobenzene-
chlorobenzene than those in benzene-carbon tetrachloride mixtures. Thus,
dipole-dipole attractions are stronger than induced dipole-induced dipole
attractions. Similar plots for the other four systems are given in Fig. 4.9.
Molecular interaction parameter values are positive and a maximum
molecular interaction parameter value is obtained for each system. In
ethanol-water system, molecular interaction parameter value is the highest at
X1 = 0.2. Thus, stronger intermolecular hydrogen bonding is present in this
system even at lower concentration. In the other cases, the maximum ‘χU’
values are observed at X1 = 0.4 – 0.6 and molecular interactions are stronger
in this concentration range in these binary systems.
4.2.5. Relaxation Time (ττττ)
The values of relaxation time (τ) are calculated for the six binary
systems from coefficient of viscosity, density and ultrasonic velocity values.
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94
The relaxation time values are given in Tables 4.1, 4.3, 4.5, 4.7, 4.9 and 4.11.
There are only slight variations in relaxation time values in bromobenzene-
chlorobenzene and benzene-carbon tetrachloride systems. In these two
systems, there is only a slight increase in the molecular interactions with
concentration. However, in the case of ethanol-water and ethanol-pyridine
systems, relaxation time values increase significantly with increase in
concentration and the interaction between the molecules of components is
stronger than the attractive forces between the molecules of each component.
But in the case of other two systems, relatively weaker interactions exist
between the molecules of the two components and stronger intermolecular
interactions exist between the molecules of each component.
4.2.6. Free Length (Lf)
The free length (Lf) of a system is a measure of intermolecular attraction
between the components in binary mixtures. The increase in free length
indicates weakening of intermolecular interaction. From the data in Tables
4.1 and 4.3, it is seen that free length remains constant in the case of
benzene-carbon tetrachloride and bromobenzene-chlorobenzene systems. The
free length values for various compositions of the four binary mixtures are
given in Tables 4.5, 4.7, 4.9 and 4.11. In the case of binary systems of
ethanol with water, p-cresol, phenol and pyridine, the free length values
increase with increase in concentration of ethanol. This shows that the
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95
intramolecular attraction weakens at higher concentration and intermolecular
attractions between ethanol and water molecules dominate at higher
concentration.
4.2.7. Internal Pressure (ππππi)
The internal pressure (πi) in a binary mixture is a measure of
intermolecular attraction between the components. The internal pressure
values for various compositions for all the six systems have been obtained
from the equation suggested by Suryanarayana31. The internal pressure
values for benzene-carbon tetrachloride system and bromobenzene-
chlorobenzene system are given in Tables 4.1 and 4.3 respectively. The
internal pressure values increase slightly with increase in concentration for
both the systems indicating the existence of relatively weak interactions in
these two systems.
The internal pressure values for the binary mixtures of ethanol with
water, p-cresol, phenol and pyridine are given in Tables 4.5, 4.7, 4.9 and 4.11
and the corresponding plots are given in Fig.4.10. It is seen that the internal
pressure is maximum for ethanol-water mixture suggesting strong
intermolecular hydrogen bonding which may be due to the high polarity of
water. The slight increase in internal pressure value with concentration in
other systems indicates the existence of molecular interactions in these
systems.
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96
4.2.8. Cohesive Energy (CE)
The cohesive energy (CE) in a liquid is indicative of the attractive force
existing between the molecules. When two liquids are mixed, there is
molecular attraction between the molecules of components and hence, the
cohesive energy is high. The cohesive energy values for all the binary systems
are given in Tables 4.1, 4.3, 4.5, 4.7, 4.9 and 4.11. The corresponding plots
are given in Figs. 4.4 and 4.11. The value of cohesive energy decreases with
increase in concentration in the case of benzene-carbon tetrachloride which
may be due to weak induced dipole-induced dipole interaction in the system.
However, in bromobenzene-chlorobenzene system, cohesive energy
increases with increase in the mole fraction of bromobenzene. This suggests
that intermolecular interaction increases with the concentration of
bromobenzene which may be due to existence of stronger dipole-dipole
attraction in this system.
In ethanol-water and ethanol-pyridine systems, cohesive energy value
increases with increase in concentration of ethanol. This is due to strong
intermolecular attraction between the molecules of the components. However,
in the case of systems containing phenol and p-cresol, there is a decrease in
cohesive energy values. Phenols are associated liquids and ethanol molecules
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97
may disrupt the association due to intermolecular attraction. Consequently,
the cohesive energy decreases.
4.2.9. Free Volume (Vf) and Available Volume (Va)
The free volume (Vf) and available volume (Va) values are calculated and
presented in Tables 4.1 – 4.12 for all the binary systems investigated. It is
found that for all the systems at 303 K, free volume increases with increase in
concentration except for bromobenzene-chlorobenzene and ethanol-pyridine
mixtures. But the calculated available volume increases with increase in
concentration for all the systems except bromobenzene-chlorobenzene
system.
4.2.10. Excess Parameters
The excess acoustical parameters can be used to find out the extent of
deviation from ideal behaviour in binary liquid mixtures. These values are
calculated for all the six binary systems for different mole fractions at 303K.
These values are presented in Tables 4.2, 4.4, 4.6, 4.8, 4.10 and 4.12 and the
corresponding plots are given in Figs. 4.5, 4.6, 4.12 and 4.13. It may be
pointed out that the excess adiabatic compressibility (κE), excess free length
(LfE) and excess available volume (VaE) are negative for almost all compositions
of ethanol with water, p-cresol, phenol and pyridine. This indicates that the
attractive forces between the molecules of components are stronger than the
intramolecular attractions in each component. Further, excess acoustical
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98
parameters are more negative for binary mixtures containing equimolar
concentrations of the two components suggesting that the attractive forces
are significant at moderate concentration. It may be pointed out here that
excess acoustic impedance increases at higher mole fractions of the first
component in all the systems except bromobenzene-chlorobenzene and
benzene-carbon tetrachloride system. This indicates that at higher
concentration, the repulsive forces may dominate and the two systems
bromobenzene-chlorobenzene and benzene-carbon tetrachloride differ from
the other four in the intermolecular attraction.
4.3. CONCLUSION
The various acoustical parameters such as adiabatic compressibility,
absorption coefficient, relaxation time, free length, free volume, internal
pressure, cohesive energy, acoustic impedance and available volume, have
been evaluated from the measured ultrasonic velocity, density and viscosity
values for the six binary mixtures. The value of molecular interaction
parameter (χU) indicates the strength of molecular interactions. The excess
thermodynamic parameters such as excess ultrasonic velocity, excess
compressibility, excess free volume, excess free length and excess impedance
have been determined for all the six binary liquid mixtures. These acoustical
properties and their trend with concentration suggest that very weak
interactions of induced dipole-induced dipole type are present in benzene-
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99
carbon tetrachloride system, while relatively strong dipole-dipole attraction
exists in bromobenzene-chlorobenzene binary system. In the other four
systems containing ethanol as common component, strong intermolecular
hydrogen bonds are present and ethanol acts as structure breaker for water
clusters. In ethanol-pyridine system, there are strong dipole-dipole
attractions. However, in ethanol-phenol and ethanol-p-cresol systems,
ethanol molecules break the intramolecular hydrogen bonds present in the
phenolic compounds and with increase in the mole fraction of ethanol, there
are strong intermolecular attractions between ethanol and phenol molecules.
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100
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19. Prabhavathi, C.L., Sivakumar, K., Venkateswarlu, P. and Raman, G.K., Ind. J. Chem.,
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21. Kannappan, V., and Jaya Shanthi, R Ind. J. Pure & Appl. Phys., 43, 2005, 750.
22. Aminabhavi, T.M., Manjeshwar, L.S., Halligudi, S.B. and Balundgi, R.H., Ind. J.
Chem., 28A, 1989, 217.
23. Roshan Abraham, Abdul Khadar, M. and Asokan, C.V., Acoustics letters, 20(11),
1997, 236.
24. Sadasiva Rao, A., Vijaya Kumar Naidu, B. and Chowdoji Rao, K., J. Acous. Soc. Ind.,
28, 2000, 301.
25. Pitchai J.Victor, Debasish Das and Dilip K. Hazra, J. Ind. Chem. Soc., 81, 2004, 1045.
26. Amalendu Pal and Anil Kumar, Ind. J. Chem., 43A, 2004, 722.
27. Adgoankar, C.S. and Mulay, N.N., Ind. J. Pure & Appl. Phys., 25, 1987, 281.
28. Singh, D.P., Rarajit Kan, Harkiram Ham, Mohan Joshi and Jasbir Singh, J. Chem. Soc.
Faraday Trans., 89(21), 1993, 1737.
29. Singh, D.P. and Jasbir Singh, J. Chem. Soc. Faraday Trans., 89(21), 1993, 3955.
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Page 102
TABLE 4.1
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ),ABSORPTION COEFFICIENT (αααα/f2),
MOLECULAR INTERACTION PARAMETER (χχχχU), RELAXATION TIME (ττττ), FREE LENGTH (Lf), FREE VOLUME (Vf), INTERNAL PRESSURE (ππππi),
AND COHESSIVE ENERGY (CE) VALUES AT VARIOUS MOLE FRACTIONS OF BENZENE - CARBON TETRACHLORIDE SYSTEM
Temperature : 303 K
Mole Fraction
of first U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9
α/f2 /10-15 χχχχU /10-3 ττττ /10-13 Lf Vf /10-7 ππππi CE Component
(X1) ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 s Ao m3 atm kJ mol-1
0.000 906.0 1590.1 8.67 0.77 19.3 0.0 8.9 0.5 2.3 3865 37.9
0.108 939.6 1502.9 8.69 0.75 18.3 -13.5 8.7 0.5 2.2 3900 38.3
0.214 957.4 1435.9 8.45 0.76 17.6 -55.9 8.6 0.5 2.2 3948 38.3
0.318 982.4 1367.9 8.09 0.76 16.4 -79.5 8.2 0.5 2.2 3956 38.0
0.421 1009.8 1298.0 7.75 0.76 15.2 -95.8 7.8 0.5 2.3 3962 37.7
0.521 1049.0 1227.8 7.36 0.74 13.7 -89.4 7.3 0.5 2.3 3937 37.1
0.620 1080.2 1157.1 7.01 0.74 12.6 -95.8 6.9 0.5 2.4 3938 36.8
0.718 1122.8 1086.6 6.70 0.73 11.5 -82.3 6.5 0.5 2.4 3936 36.5
0.813 1161.4 1016.1 6.34 0.73 10.5 -75.0 6.2 0.5 2.5 3931 36.2
0.907 1210.6 944.8 6.00 0.72 9.4 -50.6 5.8 0.5 2.5 3921 35.8
1.000 1276.8 864.7 5.65 0.70 8.3 0.0 5.3 0.5 2.6 3860 35.3
Plots : Fig. 4.1 U vs Mole Fraction; Fig. 4.3 χU vs Mole Fraction;
Fig. 4.2 κ vs Mole Fraction; Fig. 4.4 CE vs Mole Fraction;
Page 103
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TABLE 4.2
ACOUSTICAL IMPEDANCE (Z), AVAILABLE VOLUME (Va), LENARD JONES POTENTIAL (LJP),
EXCESS ULTRASONIC VELOSITY (UE), EXCESS VISCOSITY (ηηηηE), EXCESS ADIABATIC COMPRESSIBILITY (κκκκ
E),
EXCESS FREE LENGTH (LfE), EXCESS FREE VOLUME (Vf
E), EXCESS ACOUSTICAL IMPEDANCE (ZE) AND EXCESS
AVAILABLE VOLUME (VaE) VALUES AT VARIOUS MOLE FRACTIONS OF BENZENE - CARBON TETRACHLORIDE SYSTEM
Temperature : 303 K
Mole Fraction
of first Z /105 Va /10-5 LJP UE ηηηηE /10-5 κκκκE /10
-12 VfE/10-8 Lf
E/10-13 ZE /105 VaE /10-6
Component (X1) kg-2s-1 m3 ms-1 Nsm-2 kg-1ms2 m3 m kg-2s-1 m3
0.000 14.4 4.2 0.8 - - - - - - -
0.108 14.1 4.0 1.5 -6.4 3.35 -6.34 -1.1 -2.3 0.1 0.6
0.214 13.7 3.8 1.9 -27.9 4.20 5.77 -1.8 2.1 0.1 1.6
0.318 13.4 3.7 2.5 -41.6 3.89 9.37 -1.8 3.5 0.1 2.2
0.421 13.1 3.5 3.3 -52.1 3.66 13.24 -1.8 4.9 0.1 2.7
0.521 12.9 3.2 4.4 -50.3 2.93 3.56 -1.3 1.4 0.2 2.5
0.620 12.5 3.0 5.5 -55.8 2.51 9.68 -1.3 3.6 0.2 2.8
0.718 12.2 2.7 7.1 -49.3 2.48 4.57 -1.2 1.8 0.2 2.4
0.813 11.8 2.5 8.9 -46.1 1.89 9.65 -1.0 3.6 0.1 2.2
0.907 11.4 2.2 11.7 -31.9 1.51 7.56 -0.8 2.8 0.1 1.5
1.000 11.0 1.8 16.7 - - - - - - -
Plots : Fig.4.5 UE vs Mole Fraction;
Fig.4.6 ZE vs Mole Fraction;
Page 104
104
TABLE 4.3
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ),ABSORPTION COEFFICIENT (αααα/f2),
MOLECULAR INTERACTION PARAMETER (χχχχU), RELAXATION TIME (ττττ), FREE LENGTH (Lf), FREE VOLUME (Vf), INTERNAL PRESSURE (ππππi),
AND COHESSIVE ENERGY (CE) VALUES AT VARIOUS MOLE FRACTIONS OF BROMOBENZENE - CHLOROBENZENE SYSTEM
Temperature : 303 K
Mole Fraction
of first U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9
α/f2 /10-15 χχχχU /10-3 ττττ /10-13 Lf Vf /10-7 ππππi CE
Component (X1) ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 s Ao m3 atm kJ mol-1
0.000 1241.7 1102.0 7.28 0.59 9.1 0.0 5.7 0.5 3.0 3411 35.3
0.097 1225.6 1005.2 6.63 0.66 9.4 -8.6 5.9 0.5 3.6 2949 34.7
0.195 1214.8 1036.9 6.81 0.65 9.6 -8.5 5.9 0.5 3.6 2935 34.8
0.294 1201.2 1071.7 7.14 0.65 10.1 -13.0 6.2 0.5 3.5 2966 35.2
0.393 1190.8 1103.0 7.35 0.64 10.4 -12.1 6.3 0.5 3.5 2959 35.3
0.493 1179.2 1138.7 7.46 0.63 10.5 -13.2 6.3 0.5 3.5 2943 35.2
0.593 1168.6 1170.3 7.66 0.63 10.8 -12.4 6.4 0.5 3.5 2936 35.3
0.694 1159.2 1203.8 7.95 0.62 11.2 -9.5 6.6 0.5 3.4 2950 35.6
0.795 1149.6 1235.9 8.25 0.61 11.6 -6.7 6.7 0.5 3.3 2961 35.9
0.897 1139.4 1271.3 8.46 0.61 11.8 -4.9 6.8 0.5 3.3 2963 36.0
1.000 1130.8 1494.0 9.90 0.52 12.1 0.0 6.9 0.5 2.7 3463 36.9
Plots : Fig. 4.1 U vs Mole Fraction; Fig. 4.3 χU vs Mole Fraction;
Fig. 4.2 κ vs Mole Fraction; Fig. 4.4 CE vs Mole Fraction;
Page 105
105
TABLE 4.4
ACOUSTICAL IMPEDANCE (Z), AVAILABLE VOLUME (Va), LENARD JONES POTENTIAL (LJP),
EXCESS ULTRASONIC VELOSITY (UE), EXCESS VISCOSITY (ηηηηE), EXCESS ADIABATIC COMPRESSIBILITY (κκκκ
E),
EXCESS FREE LENGTH (LfE), EXCESS FREE VOLUME (Vf
E), EXCESS ACOUSTICAL IMPEDANCE (ZE) AND
EXCESS AVAILABLE VOLUME (VaE) VALUES AT VARIOUS MOLE FRACTIONS OF BROMOBENZENE - CHLOROBENZENE SYSTEM
Temperature : 303 K
Mole Fraction
of first Z /105 Va /10-5 LJP UE ηηηηE /10-5 κκκκE /10
-12 VfE/10-8 Lf
E/10-13 ZE /105 VaE /10-6
Component (X1) kg-2s-1 m3 ms-1 Nsm-2 kg-1ms2 m3 m kg-2s-1 m3
0.000 13.7 2.3 13.8 - - - - - - -
0.097 12.3 2.7 12.6 -5.3 -9.02 80.04 6.1 31.9 -1.7 3.6
0.195 12.6 2.8 11.9 -5.2 -9.88 77.64 6.5 31.2 -1.7 3.7
0.294 12.9 2.9 11.1 -7.9 -9.11 77.21 5.5 31.2 -1.8 4.0
0.393 13.1 3.0 10.5 -7.3 -9.61 76.36 5.7 31.1 -1.8 4.2
0.493 13.4 3.1 9.8 -7.8 -11.09 75.04 6.4 30.8 -1.8 4.3
0.593 13.7 3.2 9.3 -7.3 -11.77 75.74 6.6 31.2 -1.9 4.4
0.694 14.0 3.3 8.8 -5.5 -11.48 74.78 6.1 31.0 -2.0 4.4
0.795 14.2 3.4 8.3 -3.9 -11.17 75.45 5.7 31.4 -2.0 4.5
0.897 14.5 3.5 7.8 -2.8 -11.77 75.70 5.9 31.6 -2.1 4.5
1.000 16.9 3.1 7.5 - - - - - - -
Plots : Fig.4.5 UE vs Mole Fraction;
Fig.4.6 ZE vs Mole Fraction;
Page 106
106
TABLE 4.5
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ),ABSORPTION COEFFICIENT (αααα/f2),
MOLECULAR INTERACTION PARAMETER (χχχχU), RELAXATION TIME (ττττ), FREE LENGTH (Lf), FREE VOLUME (Vf),
INTERNAL PRESSURE (ππππi), AND COHESSIVE ENERGY (CE) VALUES AT VARIOUS MOLE FRACTIONS OF ETHANOL - WATER SYSTEM
Temperature : 303 K
Mole Fraction
of first U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9
α/f2 /10-15 χχχχU /10-3 ττττ /10-13 Lf Vf /10-7 ππππi CE
Component (X1) ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 s Ao m3 atm kJ mol-1
0.000 1510.0 995.7 7.98 0.44 6.1 0.0 4.7 0.4 0.2 25701 47.1
0.033 1563.2 873.4 8.27 0.47 6.5 89.6 5.2 0.4 0.2 22221 48.8
0.072 1596.4 863.2 9.82 0.45 7.4 158.6 6.0 0.4 0.2 22274 52.3
0.117 1611.2 851.7 11.97 0.45 8.8 207.6 7.2 0.4 0.2 22581 57.2
0.171 1584.0 837.9 13.63 0.48 10.8 199.9 8.6 0.4 0.2 22181 61.1
0.236 1530.2 821.4 14.33 0.52 12.8 158.6 9.9 0.5 0.2 20869 63.4
0.317 1470.4 804.8 14.45 0.57 14.9 116.7 11.1 0.5 0.2 19030 64.4
0.419 1401.6 783.4 14.00 0.65 17.1 72.9 12.1 0.5 0.2 16738 64.4
0.553 1333.2 763.1 12.84 0.74 18.7 46.7 12.6 0.5 0.2 14058 62.6
0.736 1267.2 739.3 11.35 0.84 19.8 53.2 12.7 0.6 0.3 11244 59.6
1.000 1136.0 789.0 8.91 0.98 20.3 0.0 11.7 0.6 0.5 8955 53.0
Plots : Fig. 4.7 U vs Mole Fraction; Fig. 4.10 πi vs Mole Fraction;
Fig. 4.8 κ vs Mole Fraction; Fig. 4.11 CE vs Mole Fraction;
Fig. 4.9 χU vs Mole Fraction;
Page 107
107
TABLE 4.6
ACOUSTICAL IMPEDANCE (Z), AVAILABLE VOLUME (Va), LENARD JONES POTENTIAL (LJP),
EXCESS ULTRASONIC VELOSITY (UE), EXCESS VISCOSITY (ηηηηE), EXCESS ADIABATIC COMPRESSIBILITY (κκκκ
E),
EXCESS FREE LENGTH (LfE), EXCESS FREE VOLUME (Vf
E), EXCESS ACOUSTICAL IMPEDANCE (ZE) AND
EXCESS AVAILABLE VOLUME (VaE) VALUES AT VARIOUS MOLE FRACTIONS OF ETHANOL - WATER SYSTEM
Temperature : 303 K
Mole Fraction
of first Z /105 Va /10-5 LJP UE ηηηηE /10-5 κκκκE /10
-12 VfE/10-8 Lf
E/10-13 ZE /105 VaE /10-6
Component (X1) kg-2s-1 m3 ms-1 Nsm-2 kg-1ms2 m3 m kg-2s-1 m3
0.000 15.0 0.1 93.7 - - - - - - -
0.033 13.7 0.0 247.9 65.6 0.03 10.03 0.1 -29.3 -1.1 -1.0
0.072 13.8 0.0 2653.7 113.3 0.18 -24.80 -0.4 -27.7 -0.8 -2.1
0.117 13.7 0.0 -870.1 145.0 0.39 -51.65 -0.8 -25.8 -0.6 -3.0
0.171 13.3 0.0 587.0 138.0 0.55 -57.50 -1.2 -23.6 -0.7 -3.4
0.236 12.6 0.1 124.5 108.6 0.61 -48.57 -1.4 -20.8 -1.0 -3.4
0.317 11.8 0.3 61.1 79.0 0.62 -37.51 -1.5 -17.5 -1.3 -3.3
0.419 11.0 0.5 35.4 48.4 0.56 -17.86 -1.6 -13.2 -1.5 -3.0
0.553 10.2 0.7 23.0 30.1 0.43 -2.83 -1.5 -7.6 -1.5 -2.5
0.736 9.4 1.1 15.8 32.4 0.27 3.27 -1.1 0.0 -1.2 -1.8
1.000 9.0 1.7 7.7 - - - - - - -
Plots : Fig.4.12 UE vs Mole Fraction;
Fig.4.13 ZE vs Mole Fraction;
Page 108
108
TABLE 4.7
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ),ABSORPTION COEFFICIENT (αααα/f2),
MOLECULAR INTERACTION PARAMETER (χχχχU), RELAXATION TIME (ττττ), FREE LENGTH (Lf), FREE VOLUME (Vf),
INTERNAL PRESSURE (ππππi), AND COHESSIVE ENERGY (CE) VALUES AT VARIOUS MOLE FRACTIONS OF ETHANOL - p-CRESOL SYSTEM
Temperature : 303 K Mole
Fraction
of first U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9
α/f2 /10-15 χχχχU /10-3 ττττ /10-13 Lf Vf /10-7 ππππi CE Component
(X1) ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 s Ao m3 atm kJ mol-1
0.000 1450.4 1034.0 90.15 0.46 75.1 0.0 55.3 0.4 0.1 11152 118.2
0.166 1447.0 888.7 50.64 0.54 49.4 71.0 36.3 0.5 0.2 8502 94.8
0.309 1425.6 876.1 41.65 0.56 43.1 109.9 31.2 0.5 0.2 8599 88.4
0.434 1398.2 857.1 29.36 0.60 32.9 132.5 23.4 0.5 0.3 7992 76.7
0.544 1372.0 838.3 23.04 0.63 28.0 150.2 19.5 0.5 0.3 7802 70.1
0.642 1337.4 817.5 18.97 0.68 25.5 147.2 17.3 0.5 0.4 7786 65.9
0.729 1303.4 797.9 15.50 0.74 23.1 139.0 15.2 0.5 0.4 7723 61.7
0.807 1269.8 775.1 12.89 0.80 21.3 125.9 13.7 0.6 0.5 7684 58.3
0.878 1229.2 751.8 10.61 0.88 20.0 95.3 12.4 0.6 0.6 7609 55.0
0.942 1192.6 730.1 9.62 0.96 20.4 67.3 12.4 0.6 0.5 7893 54.4
1.000 1136.0 789.0 8.91 0.98 20.3 0.0 11.7 0.6 0.5 8955 53.0
Plots : Fig. 4.7 U vs Mole Fraction; Fig. 4.10 πi vs Mole Fraction;
Fig. 4.8 κ vs Mole Fraction; Fig. 4.11 CE vs Mole Fraction;
Fig. 4.9 χU vs Mole Fraction;
Page 109
109
TABLE 4.8
ACOUSTICAL IMPEDANCE (Z), AVAILABLE VOLUME (Va), LENARD JONES POTENTIAL (LJP),
EXCESS ULTRASONIC VELOSITY (UE), EXCESS VISCOSITY (ηηηηE), EXCESS ADIABATIC COMPRESSIBILITY (κκκκ
E),
EXCESS FREE LENGTH (LfE), EXCESS FREE VOLUME (Vf
E), EXCESS ACOUSTICAL IMPEDANCE (ZE) AND
EXCESS AVAILABLE VOLUME (VaE) VALUES AT VARIOUS MOLE FRACTIONS OF ETHANOL - p-CRESOL SYSTEM
Temperature : 303 K
Mole Fraction
of first Z /105 Va /10-5 LJP UE ηηηηE /10-5 κκκκE /10
-12 VfE/10-8 Lf
E/10-13 ZE /105 VaE /10-6
Component (X1) kg-2s-1 m3 ms-1 Nsm-2 kg-1ms2 m3 m kg-2s-1 m3
0.000 15.0 1.0 51.2 - - - - - - -
0.166 12.9 1.1 49.7 48.8 -2.60 -9.02 0.1 -24.5 -1.1 -0.4
0.309 12.5 1.1 42.0 72.4 -2.34 -59.61 -0.2 -18.4 -0.6 -0.9
0.434 12.0 1.2 34.6 84.3 -2.55 -89.77 0.0 -13.1 -0.4 -0.9
0.544 11.5 1.3 29.1 92.7 -2.29 -110.30 0.2 -8.4 -0.2 -1.0
0.642 10.9 1.4 23.6 88.8 -1.90 -111.07 0.2 -4.2 -0.2 -0.7
0.729 10.4 1.5 19.4 82.1 -1.54 -102.64 0.4 -0.5 -0.2 -0.4
0.807 9.8 1.5 16.1 73.1 -1.17 -81.11 0.6 2.8 -0.3 -0.1
0.878 9.2 1.7 12.9 54.7 -0.83 -37.77 1.0 5.8 -0.5 0.5
0.942 8.7 1.7 10.6 38.2 -0.40 11.44 0.6 8.5 -0.6 0.8
1.000 9.0 1.7 7.7 - - - - - - -
Plots : Fig.4.12 UE vs Mole Fraction;
Fig.4.13 ZE vs Mole Fraction;
Page 110
110
TABLE 4.9
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ),ABSORPTION COEFFICIENT (αααα/f2),
MOLECULAR INTERACTION PARAMETER (χχχχU), RELAXATION TIME (ττττ), FREE LENGTH (Lf), FREE VOLUME (Vf),
INTERNAL PRESSURE (ππππi), AND COHESSIVE ENERGY (CE) VALUES AT VARIOUS MOLE FRACTIONS OF ETHANOL - PHENOL SYSTEM
Temperature : 303 K
Mole Fraction
of first U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9
α/f2 /10-15 χχχχU /10-3 ττττ /10-13 Lf Vf /10-7 ππππi CE
Component (X1) ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 s Ao m3 atm kJ mol-1
0.000 1454.8 1066.0 52.75 0.44 42.3 0.0 31.2 0.4 0.1 10223 91.4
0.144 1458.4 925.0 39.08 0.51 35.8 71.4 26.5 0.4 0.2 8739 83.5
0.274 1436.2 903.8 31.71 0.54 31.1 103.2 22.7 0.5 0.3 8521 77.3
0.393 1406.8 882.0 24.55 0.57 26.3 119.8 18.7 0.5 0.3 8118 70.1
0.502 1379.0 857.3 18.14 0.61 21.2 134.3 14.8 0.5 0.4 7522 62.2
0.602 1346.2 834.2 16.48 0.66 21.3 136.2 14.5 0.5 0.4 7742 61.3
0.694 1316.0 812.2 14.13 0.71 20.1 138.1 13.4 0.5 0.5 7731 58.6
0.779 1279.6 786.9 12.30 0.78 19.6 125.0 12.7 0.6 0.5 7769 56.7
0.858 1234.8 762.7 10.94 0.86 20.0 92.8 12.5 0.6 0.5 7920 55.6
0.932 1200.4 736.9 9.55 0.94 19.7 74.9 12.0 0.6 0.6 7951 54.0
1.000 1136.0 789.0 8.91 0.98 20.3 0.0 11.7 0.6 0.5 8955 53.0 Plots : Fig. 4.7 U vs Mole Fraction; Fig. 4.10 πi vs Mole Fraction;
Fig. 4.8 κ vs Mole Fraction; Fig. 4.11 CE vs Mole Fraction;
Fig. 4.9 χU vs Mole Fraction;
Page 111
111
TABLE 4.10
ACOUSTICAL IMPEDANCE (Z), AVAILABLE VOLUME (Va), LENARD JONES POTENTIAL (LJP),
EXCESS ULTRASONIC VELOSITY (UE), EXCESS VISCOSITY (ηηηηE), EXCESS ADIABATIC COMPRESSIBILITY (κκκκ
E),
EXCESS FREE LENGTH (LfE), EXCESS FREE VOLUME (Vf
E), EXCESS ACOUSTICAL IMPEDANCE (ZE) AND
EXCESS AVAILABLE VOLUME (VaE) VALUES AT VARIOUS MOLE FRACTIONS OF ETHANOL - PHENOL SYSTEM AT 303.15 K
Temperature : 303 K
Mole Fraction
of first Z /105 Va /10-5 LJP UE ηηηηE /10-5 κκκκE /10
-12 VfE/10-8 Lf
E/10-13 ZE /105 VaE /10-6
Component (X1) kg-2s-1 m3 ms-1 Nsm-2 kg-1ms2 m3 m kg-2s-1 m3
0.000 15.5 0.8 53.1 - - - - - - -
0.144 13.5 0.8 54.8 49.5 -0.74 -12.23 1.2 -24.8 -1.1 -1.0
0.274 13.0 0.9 45.6 68.8 -0.90 -54.44 1.0 -19.3 -0.7 -1.3
0.393 12.4 1.0 36.7 77.4 -1.10 -82.11 1.1 -14.4 -0.5 -1.2
0.502 11.8 1.1 30.4 84.2 -1.26 -100.25 1.8 -9.8 -0.4 -1.2
0.602 11.2 1.2 24.8 83.3 -0.99 -106.04 1.3 -5.6 -0.3 -1.0
0.694 10.7 1.3 20.8 82.4 -0.82 -106.22 1.2 -1.8 -0.3 -0.9
0.779 10.1 1.4 17.0 73.2 -0.63 -86.94 1.1 1.8 -0.3 -0.5
0.858 9.4 1.6 13.3 53.6 -0.42 -45.65 0.8 5.1 -0.5 0.2
0.932 8.8 1.7 11.0 42.6 -0.24 -3.39 0.8 8.1 -0.6 0.4
1.000 9.0 1.7 7.7 - - - - - - -
Plots : Fig.4.12 UE vs Mole Fraction;
Fig.4.13 ZE vs Mole Fraction;
Page 112
112
TABLE 4.11
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ),ABSORPTION COEFFICIENT (αααα/f2),
MOLECULAR INTERACTION PARAMETER (χχχχU), RELAXATION TIME (ττττ), FREE LENGTH (Lf), FREE VOLUME (Vf),
INTERNAL PRESSURE (ππππi), AND COHESSIVE ENERGY (CE) VALUES AT VARIOUS MOLE FRACTIONS OF ETHANOL - PYRIDINE SYSTEM
Temperature : 303 K
Mole Fraction
of first U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9
α/f2 /10-15 χχχχU /10-3 ττττ /10-13 Lf Vf /10-7 ππππi CE
Component (X1) ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 s Ao m3 atm kJ mol-
1
0.000 1393.0 981.0 7.71 0.53 7.6 0.0 5.4 0.5 3.1 3213 35.9
0.133 1371.8 846.9 6.77 0.63 8.1 19.2 5.7 0.5 3.2 3092 36.2
0.257 1348.2 832.6 6.64 0.66 8.6 32.1 5.9 0.5 2.7 3414 36.9
0.372 1327.6 817.0 6.60 0.69 9.1 47.0 6.1 0.5 2.4 3766 37.9
0.479 1304.4 801.9 6.68 0.73 9.9 55.2 6.5 0.5 2.0 4183 39.3
0.580 1282.6 784.9 6.74 0.77 10.7 63.1 7.0 0.6 1.7 4611 40.6
0.674 1261.6 769.7 6.89 0.82 11.7 69.9 7.5 0.6 1.4 5109 42.3
0.763 1235.0 752.7 7.08 0.87 13.1 64.7 8.2 0.6 1.2 5663 44.2
0.847 1206.0 736.1 7.34 0.93 14.9 52.8 9.1 0.6 0.9 6299 46.5
0.926 1180.6 721.7 7.53 0.99 16.7 44.6 10.0 0.6 0.8 6966 48.6
1.000 1136.0 789.0 8.91 0.98 20.3 0.0 11.7 0.6 0.5 8955 53.0
Plots : Fig. 4.7 U vs Mole Fraction; Fig. 4.10 πi vs Mole Fraction;
Fig. 4.8 κ vs Mole Fraction; Fig. 4.11 CE vs Mole Fraction;
Fig. 4.9 χU vs Mole Fraction;
Page 113
113
TABLE 4.12
ACOUSTICAL IMPEDANCE (Z), AVAILABLE VOLUME (Va), LENARD JONES POTENTIAL (LJP),
EXCESS ULTRASONIC VELOSITY (UE), EXCESS VISCOSITY (ηηηηE), EXCESS ADIABATIC COMPRESSIBILITY (κκκκ
E),
EXCESS FREE LENGTH (LfE), EXCESS FREE VOLUME (Vf
E), EXCESS ACOUSTICAL IMPEDANCE (ZE) AND
EXCESS AVAILABLE VOLUME (VaE) VALUES AT VARIOUS MOLE FRACTIONS OF ETHANOL - PYRIDINE SYSTEM
Temperature : 303 K
Mole Fraction
of first Z /105 Va /10-5 LJP UE ηηηηE /10-5 κκκκE /10
-12 VfE/10-8 Lf
E/10-13 ZE /105 VaE /10-6
Component (X1) kg-2s-1 m3 ms-1 Nsm-2 kg-1ms2 m3 m kg-2s-1 m3
0.000 13.7 1.4 33.4 - - - - - - -
0.133 11.6 1.6 29.1 13.0 -0.11 41.39 4.1 -28.4 -1.4 1.9
0.257 11.2 1.7 25.1 21.2 -0.14 18.29 3.1 -22.8 -1.2 1.9
0.372 10.8 1.7 22.2 30.1 -0.16 -0.64 2.3 -17.6 -1.1 1.7
0.479 10.5 1.7 19.5 34.6 -0.16 -11.31 1.2 -12.7 -1.0 1.6
0.580 10.1 1.7 17.2 38.7 -0.17 -15.76 0.8 -8.1 -0.9 1.5
0.674 9.7 1.7 15.4 41.9 -0.16 -17.13 0.5 -3.8 -0.8 1.2
0.763 9.3 1.8 13.3 38.1 -0.15 -2.91 0.3 0.2 -0.8 1.3
0.847 8.9 1.8 11.4 30.6 -0.14 21.93 0.3 4.0 -0.8 1.4
0.926 8.5 1.8 9.9 25.5 -0.13 46.03 0.8 7.6 -0.8 1.3
1.000 9.0 1.7 7.7 - - - - - - -
Plots : Fig.4.12 UE vs Mole Fraction;
Fig.4.13 ZE vs Mole Fraction;
Page 114
Fig. 4.1 Plots of Ultrasonic Velocity vs Mole Fraction of first component
900
1000
1100
1200
1300
0.0 0.2 0.4 0.6 0.8 1.0
Mole Fraction of first component X1
U,
ms
-1
BZ-CTC BBZ-CBZ
Fig. 4.2 Plots of Adiabatic compressibility vs Mole Fraction of first
component
0.5
0.6
0.7
0.8
0.0 0.2 0.4 0.6 0.8 1.0
Mole Fraction of first component X1
κκ κκ /10
-9, k
g-1
ms
2
BZ-CTC BBZ-CBZ
Page 115
115
Fig. 4.3 Plots of Molecular interaction parameter vs Mole Fraction of
first component
-120
-100
-80
-60
-40
-20
0
0.0 0.2 0.4 0.6 0.8 1.0 1.2
Mole Fraction of first component X1
χχ χχU
/10
-3,
ms
-1
BZ-CTC BBZ-CBZ
Temperature : 303 K
Fig. 4.4 Plots of Cohessive Energy vs Mole Fraction of first component
32
34
36
38
40
0.0 0.2 0.4 0.6 0.8 1.0
Mole Fraction of first component X1
CE
, kJ m
ol-1
BZ-CTC BBZ-CBZ
Page 116
116
Fig. 4.5 Plots of Excess Ultrasonic velocity vs Mole Fraction of first
component
-75
-50
-25
0
0.0 0.2 0.4 0.6 0.8 1.0
Mole Fraction of first component X1
UE, m
s-1
BZ-CTC BBZ-CBZ
Temperature : 303 K
Fig. 4.6 Plots of Excess Acoustic impedance vs Mole Fraction of first
component
-3
-2
-1
0
1
0.0 0.2 0.4 0.6 0.8 1.0
Mole Fraction of first component X1
ZE /
10
5, k
g-2
s-1
BZ-CTC BBZ-CBZ
Temperature : 303 K
Page 117
117
Fig. 4.7 Plots of Ultrasonic Velocity vs Mole Fraction of first
components
1100
1300
1500
1700
0.0 0.2 0.4 0.6 0.8 1.0
Mole Fraction of first component X1
U,
ms
-1
EL-Water
EL-PCL
EL-PL
EL-PYR
Temperature : 303 K
Fig. 4.8 Plots of Adiabatic Compressibility vs Mole Fraction of first
components
0.4
0.6
0.8
1.0
1.2
0.0 0.2 0.4 0.6 0.8 1.0
Mole Fraction of first component X1
κκ κκ /
10
-9,
kg
-1 m
s2
EL-WaterEL-PCLEL-PLEL-PYR
Page 118
118
Fig. 4.9 Plots of Molecular interaction parameter vs Mole Fraction of
first components
0
50
100
150
200
250
0.0 0.2 0.4 0.6 0.8 1.0
Mole Fraction of first component X1
χχ χχU /
10
-3,
ms
-1
EL-WaterEL-PCLEL-PLEL-PYR
Fig. 4.10 Plots of Internal Pressure vs Mole Fraction of first components
2000
7000
12000
17000
22000
0.0 0.2 0.4 0.6 0.8 1.0
Mole Fraction of first component X1
ππ ππi,
atm
EL-WaterEL-PCLEL-PLEL-PYR
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119
Fig. 4.11 Plots of Cohessive Energy vs Mole Fraction of first
components
30
50
70
90
110
130
0.0 0.2 0.4 0.6 0.8 1.0
Mole Fraction of first component X1
CE
, kJ m
ol-1
EL-WaterEL-PCLEL-PLEL-PYR
Fig. 4.12 Plots of Excess Ultrasonic velocity vs Mole Fraction of first
components
0
40
80
120
160
0.0 0.2 0.4 0.6 0.8 1.0
Mole Fraction of first component X1
UE,
ms
-1
EL-WaterEL-PCLEL-PLEL-PYR
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120
Fig. 4.13 Plots of Excess Acoustic impedance vs Mole Fraction of first
components
-1.6
-1.2
-0.8
-0.4
0.0
0.0 0.2 0.4 0.6 0.8 1.0 1.2Mole Fraction of first component X1
ZE /
10
5,
kg
-2 s
-1
EL-WaterEL-PCLEL-PLEL-PYR
Temperature :303 K
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122
CHAPTER – 5
DETERMINATION OF STABILITY CONSTANTS FOR THE CHARGE TRANSFER COMPLEXES OF CERTAIN
HYDROCARBONS AND IODINE IN n-HEXANE SOLUTION BY ULTRASONIC METHOD
5.1. INTRODUCTION
Aromatic hydrocarbons are rich in π-electron and favour the formation
of charge transfer complexes with electron deficient molecules. This may be
due to the intermolecular attractive forces or through dipole-dipole
interaction with electron deficient molecules. The halogenation reactions are
widely employed by synthetic organic chemists in the preparation of several
insecticides and pharmaceuticals1-5. Both kinetic and non-kinetic methods
have been employed to establish the mechanism of this reaction6-8. It has
been suggested that halogen combines with donor molecule to form donor-
acceptor complexes. There is equilibrium between the complex and the donor
and acceptor molecules involved in the complexation. Thus, the formation of
charge transfer complex is the first step in halogenation. These donor-
acceptor complexes are called π-complexes. The formation of π−complexes
with halogens and several homocyclic aromatic compounds have been well
established by UV spectroscopy9-11. Among halogens, iodine has basic
character and it can function as an effective electron acceptor. It may form
charge transfer complexes with electron donors like aromatic hydrocarbons12.
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123
Polynuclear aromatic hydrocarbons (PAH) are potential carcinogens.
Among these, derivatives of anthracene, phenanthrene, benzo(a)pyrene are
the most health hazardous chemicals. Studies in the fresh water trout
demonstrated that trout liver microsomes actively biotransformed PAH
carcinogens into a variety of electrophilic metabolites and catalysed binding of
activated PAH molecule to DNA13. Carcinogenic polycyclic aromatic
hydrocarbons are thus metabolically activated and bind covalently to DNA,
RNA and protein in systems in which they induce biological effects14. In both
mouse skin and rodent embryo cell cultures, the carcinogenic activity of a
hydrocarbon is directly correlated with the amount of the hydrocarbon bond
to DNA and to a specific protein, namely, the h-protein15.
Recently, ultrasound has been used to detect donor-acceptor complexes
in solutions. Bhatt and co-workers16,17 have determined formation or stability
constants of charge transfer complexes by ultrasonic method. The limitation
of this method is that it can be applied to binary systems in moderate
concentrations. Further, the formation constants were found to be
concentration dependent18. Based on the assumptions of Marwein and Bhatt,
Kannappan et al19-21 showed that the deviation from ideal behaviour of any
physical properties is due to charge transfer complex formed. They deduced
the equation to calculate formation constants of charge transfer (CT)
complexes even in dilute solutions containing the donor and acceptor in non-
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124
polar solvents. They applied this equation to a large number of donor-
acceptor complexes22-24.
This chapter contains the results obtained in the investigation of
charge transfer complexes of iodine (acceptor) and six monocyclic aromatic
hydrocarbons and three polynuclear aromatic hydrocarbons (donors) in n-
hexane solution at 303 K. Here, the positive end of iodine dipole polarizes the
π-electron cloud of the polynuclear aromatic hydrocarbons25-33. The six
monocyclic aromatic hydrocarbons used as donors are mesitylene, o-xylene,
m-xylene, p-xylene, benzene and toluene while the three polynuclear aromatic
hydrocarbons are anthracene, biphenyl and naphthalene. The structures of
these donor molecules are given below.
CH3
Mesitylene
CH3H3CCH3
CH3
CH3
CH3
p - Xylene m - Xylene
CH3
CH3
o - Xylene Benzene
CH3
Toluene
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125
BiphenylAnthracene Naphthalene
The acoustical parameters such as adiabatic compressibility (κ),
absorption coefficient (α/f2), molecular interaction parameter (χU), relaxation
time (τ), free length (Lf), free volume (Vf), internal pressure (πi), cohesive energy
(CE), acoustic impedance (Z), available volume (Va), Lenard Jones Potential
(LJP) and Gibb’s free energy of activation (∆G#) are calculated at various
concentrations. The interactions between the donor and acceptor molecules
have been studied from the variation of acoustical parameters with the
concentration of donor. The stability constant (K) values are calculated for all
the nine systems in n-hexane at 303 K. From the calculated values of K, the
free energies of formation (∆G) are computed to ascertain their
thermodynamic stability.
5.2. Results and Discussion
The ultrasonic velocities (U), densities (ρ) and viscosities are determined
for n-hexane solutions containing equimolar concentrations of iodine and
each of six homocylic hydrocarbons namely, mesitylene, p-xylene, m-xylene,
o-xylene, toluene and benzene at 303 K. Tables 5.1 - 5.12 contain the
calculated acoustical parameters for the following systems. Plots of ultrasonic
velocity vs concentration for all the six systems are given in Fig. 5.1. It is
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126
evident from these plots that ultrasonic velocity (U) increases in all the
systems uniformly with increase in concentration except in mesitylene and
m-xylene systems. The increasing trend in ultrasonic velocity suggests that
the complexation increases with increase in concentration. In the case of
mesitylene and m-xylene even at lower concentration, the complexation is
significant. The measured values of ultrasonic velocity, density and viscosity
values for the three polynuclear hydrocarbons are presented in Tables 5.13 –
5.18 and the corresponding plots are given in Fig. 5.6. The ultrasonic velocity
decreases with increase in concentration in the case of biphenyl and
naphthalene. This shows that the complexation is significant even at lower
concentration in these two systems. In the case of anthracene, the ultrasonic
velocity is found to be a minimum in the concentration range 0.004 and
0.008M. Thus, the donor-acceptor complex formation is significant in this
concentration range for this system.
The adiabatic compressibility (κ) and free length (Lf) values for the nine
systems are calculated at different concentrations and are given in
Tables 5.1 – 5.18. In a given system, the adiabatic compressibility and free
length values generally remain constant at lower concentrations and
increases slightly at moderate concentrations. The same trend is followed in
all the six monocyclic hydrocarbon systems which are given in Fig. 5.2. The
slight increase in the values of adiabatic compressibility and free length at
higher concentration may be due to the formation of charge transfer
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127
complexes. In the case of polynuclear hydrocarbons, for iodine-anthracene
system, the adiabatic compressibility values are least at lower and higher
concentrations which indicates that the complexation is maximum in those
concentrations. For iodine-biphenyl system, the adiabatic compressibility
increases with increase in concentration, which shows that complexation is
maximum at lower concentrations. But the adiabatic compressibility values
remain almost constant in the case of iodine-naphthalene system. The plots
are given in Fig. 5.7. The values of adiabatic compressibility and free length of
pure components are given in Table 5.20. There is a weak bond between the
donor and acceptor molecules. Hence, the compressibility of charge transfer
complex is slightly greater than that of pure component. It may be pointed
out here that the compressibility coefficient in the concentration range
studied for almost all the systems are slightly greater than that of n-hexane.
This also confirms the formation of a weak complex between iodine and
aromatic hydrocarbons. This is also supported by the higher free length
values in all the systems compared to the free length in pure components.
Further, both adiabatic compressibility and free length values of all the
systems are almost constant at the concentrations investigated. This suggests
that similar types of complexes are formed in these systems.
The molecular interaction parameter (χU) in respect of ultrasonic
velocity values are calculated for six monocyclic aromatic systems and the
values are presented in Tables 5.1, 5.3, 5.5, 5.7, 5.9 and 5.11. Plots of
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128
molecular interaction parameter vs concentration for the aromatic monocyclic
systems are given in Fig. 5.3 while Fig. 5.8 contains similar plots for iodine–
polynuclear hydrocarbon systems. It is found that molecular interaction
parameter values are large negative for iodine-mesitylene and iodine-p-xylene
systems indicating that the extent of deviation from ideal behaviour is more
in these two systems which may probably due to complex formation. The
interaction parameter values are either positive or small negative depending
upon concentration in the iodine-m-xylene and iodine-o-xylene systems.
Relatively weaker interactions persist between donor and acceptor molecules
in these two systems and they are concentration dependent. In iodine-
benzene and iodine-toluene systems, the molecular interaction parameter
values are positive indicating a positive deviation in these two systems.
Further, relatively weak interactions are present in these two systems. It may
be pointed out that the molecular interaction parameter values are large
positive in iodine-biphenyl system, small positive in iodine-naphthalene
system and the values are both positive and negative in iodine-anthracene
system. This suggests that iodine forms a strong complex with anthracene.
The absorption coefficient (α/f2) and relaxation time (τ) values are
characteristic of the species present in solution. These values are given for
the nine systems in Tables 5.1, 5.3, 5.5, 5.7, 5.9, 5.11, 5.13, 5.15 and 5.17.
The constant values indicate that similar types of molecular interactions
between the donor and acceptor are present in these nine systems and
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129
similar types of charge transfer complexes are formed in all the nine systems
investigated.
The values of free volume (Vf), acoustic impedance (Z) and available
volume (Va) are given in Tables 5.2, 5.4, 5.6, 5.8, 5.10, 5.12, 5.14, 5.16 and
5.18. These are characteristic of the charge transfer complexes in the system
investigated. These are calculated from ultrasonic velocity and viscosity
values. It is found that the free volume and available volume do not change
significantly in these nine systems. Thus, complexation between iodine and
aromatic hydrocarbons does not influence available volume and free volume
values.
The internal pressure (πi) values for the six monocyclic hydrocarbons
are calculated and listed in Tables 5.2, 5.4, 5.6, 5.8, 5.10, and 5.12. The
internal pressure is a measure of cohesive forces between the component
molecules. The internal pressure values are generally found to decrease with
increase in concentration and then start increasing. Thus, the acceptor
polarizes the donor molecules at lower concentration and form complexes at
moderate concentrations. The plots of internal pressure vs concentration is
given in Fig. 5.4. The variation of internal pressure with concentration for
polynuclear aromatic hydrocarbons indicates that the complexation is
significant even at lower concentration as indicated by the high values of
internal pressure in these systems. Tables 5.14, 5.16 and 5.18 give the values
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130
of internal pressure for the polynuclear aromatic hydrocarbons. The
corresponding plots are given in Fig. 5.9. The acoustic impedance (Z) is
almost constant (Tables 5.2, 5.4, 5.6, 5.8, 5.10, 5.12, 5.14, 5.16 and 5.18) for
all the systems and does not vary significantly with concentration. This
suggests the existence of similar type of complexes in these systems.
The cohesive energy (CE) in liquid mixtures is an indicative of the force
of attraction between the component molecules. These values for the six
monocyclic systems are given in Tables 5.2, 5.4, 5.6, 5.8, 5.10 and 5.12, and
their corresponding plots are given in Fig. 5.5. The cohesive energy values are
found to be almost constant for a given system indicating similar type of
cohesive forces in that system. However, it varies slightly from one system to
another depending upon the strength of molecular interactions. The cohesive
energy is found to be almost constant for iodine-anthracene and iodine-
naphthalene, where it is found to decrease in the case of iodine-biphenyl
system with concentration. These values are given in Tables 5.14, 5.16 and
5.18 and the corresponding plots are given in Fig. 5.10. Thus, the cohesive
energy values in the nine systems also suggest the complexation between
iodine and aromatic hydrocarbons.
The formation constant (K) is a measure of stability of charge transfer
complex. The formation constant values are calculated for the nine systems
and the mean values are presented in Table 5.19. The formation constant
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131
values are calculated from the ultrasonic velocities. It may be noted that the
stability constant values are constant at different concentrations for a
particular system. The free energy of formation values are also computed
from the stability constant values and they are also listed in Table 5.19. It is
found that the formation constant values for these complexes are influenced
by the structure of the donor molecules. In general, the formation constant
values for polycyclic aromatic hydrocarbon are greater than those for
benzenoid systems. This is justified because, polynuclear aromatic
hydrocarbons are richer in π-electrons than monocyclic benzene derivatives
and the former can function as more effective π-electron donor than the
monocyclic aromatic hydrocarbons. Among the benzene derivatives,
mesitylene forms more stable complex with iodine than other monocyclic
aromatic hydrocarbons. This is due to the presence of three electron releasing
methyl substituents in this molecule. Similarly, xylenes also form relatively
more stable complexes with iodine than benzene and toluene. Among xylenes,
o-xylene forms a less stable complex than the other two isomeric xylenes
which may be due to steric reason. Among polynuclear aromatic
hydrocarbons, biphenyl and naphthalene contain less π-electron density and
they form less stable charge transfer complexes with iodine than with
anthracene.
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132
REFERENCES
1. Ando, T., Sumi, S., Kawate, T., Ichihara, J. and Hanafusa, T., J. Chem. Soc. Chem.
Commun., 1984, 439.
2. Coleman, A.J. and Saunders, J.E., Ultrasound Med. Biol., 15, 1989, 213.
3. Toy, M.S., Carter, M.K. and Passel, T.O., Environ. Technol., 11, 1990, 837.
4. Jayakumar, S., Karunanithi, K. and Kannappan, V., Ind. J. Pure & Appl. Phys., 34,
1996, 761.
5. Tigran, V., Chalikian, Jens Volker, Don Anafi and Kenneth J. Breslauer, J. Mol. Biol.,
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6. Jones, R.A., Advan. Heterocycl. Chem., 11, 1970, 383.
7. March, J., Advanced Organic Chemistry, 4th
Edn., John Wiley, New York, 1992.
8. Pine Stanely, H., Hendrickson, B., Cran, D.J. and Hammond, G.S., Organic Chemistry,
McGraw Hill, GB, 1989.
9. Kannappan, V., Nanjan, M.J. and Ganesan, R., Actacincia indica, 4, 1982, 196.
10. Kannappan, V., Ph.D. Thesis, University of Madras, 1982.
11. Kannappan, V., Nanjan, M.J. and Ganesan, R., Z. Physik Chem. (Neuefolge),
Frankfurt,, 91, 1984, 183.
12. Kannappan, V. and Kothai, S., Ind. J. Pure & Appl. Phys., 40, 2002, 17.
13. Ahokas, A.T., Saarni, H., Nebert, D.W. and Pelkonen, O., Chem. Biol. Interact.,
25, 1979, 103.
14. Baird, W.M. and Diamond, L., Int. J. Cancer., 22, 1978, 189.
15. Boobis, A. and Nebert, D.W., Advances in Enzyme Regulations, Ed. Weber, G.,
Pergmoun Press, Oxford and New York, 55, 1977, 339.
16. Marvein, B.L. and Bhatt, S.N., Acustica, 58, 1985, 242.
17. Marvein, B.L. and Bhatt, S.N., Thermochimica Acta., 118, 1987, 277.
18. Mehrotra, K.N., Chauhan, M. and Shukla, R.K., Phys. Chem. Liq., 21, 1990, 239.
19. Kannappan, V. and Kothai, S., J. Acous. Soc. Ind., 29, 2001, 169.
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20. Kannappan, V. and Jaya Santhi, R., J. Acous. Soc. Ind., 29, 2001, 192.
21. Kannappan, V., Jaya Santhi, R. and Malar, E.J.P., Phys. Chem. Liq., 40(4), 2002, 507.
22. Kannappan, V. and Kothai, S., J. Acous. Soc. Ind., 30, 2002, 76.
23. Mahendran, S., Ph.D. Thesis, University of Madras, 2002.
24. Kannappan, V. and Jaya Santhi, R., Ind. J. Chem., 43(A), 2004, 1431.
25. De la mare, P.B.D. and Robertson, P.W., J. Chem. Soc., 1943, 279.
26. Keefer, R.H., Ottenberg, A. and Andrews, L.J., J. Am. Chem. Soc., 78, 1956, 255.
27. Brown, T.L. and Kuboto, M., J. Am. Chem. Soc., 83, 1961, 4175.
28. Hassel, O. and Romming, C., Quart. Rev., 16, 1962, 1.
29. Marino, G., Tetrahedron, 21, 1965, 843.
30. Rao, C.N.R., Chaturvedi, G.C. and Bhat, S.N., J. Mol. Spectroscopy, 33, 1970, 554.
31. Ulrich, K. and Purt, H., J. Mol. Structure, 218, 1990, 45.
32. Jaya Santhi, R., Ph.D. Thesis, University of Madras, 2002.
33. Kothai, S., Ph.D. Thesis, University of Madras, 2003.
Page 134
TABLE 5.1
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ),
ABSORPTION COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU)
AND RELAXATION TIME (ττττ) AT VARIOUS CONCENTRATIONS OF IODINE - MESITYLENE SYSTEM
Solvent : n-hexane Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 ττττ /10-13
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 s
0.001 1050.8 634.6 3.27 1.43 11.7 -14.3 6.2
0.002 1056.6 635.0 3.27 1.41 11.5 -3.5 6.2
0.003 1054.0 635.6 3.27 1.42 11.6 -8.6 6.2
0.004 1050.0 633.9 3.28 1.43 11.7 -16.2 6.3
0.005 1048.5 634.1 3.27 1.43 11.8 -19.2 6.3
0.006 1048.9 634.3 3.27 1.43 11.7 -18.6 6.2
0.007 1049.7 633.3 3.30 1.43 11.8 -17.3 6.3
0.008 1049.1 637.2 3.29 1.43 11.7 -18.6 6.2
0.009 1048.9 634.4 3.29 1.43 11.8 -19.1 6.3
0.010 1047.6 633.9 3.28 1.44 11.8 -21.7 6.3
Plots : Fig. 5.1 U vs Concentration; Fig. 5.3 χU vs Concentration;
Fig. 5.2 κ vs Concentration;
Page 135
135
TABLE 5.2
FREE LENGTH (Lf), FREE VOLUME (Vf), INTERNAL PRESSURE (ππππi), COHESSIVE ENERGY (CE),
ACOUSTICAL IMPEDANCE (Z), AVAILABLE VOLUME (Va) AND LENARD JONES POTENTIAL (LJP),
AT VARIOUS CONCENTRATIONS OF IODINE - MESITYLENE SYSTEM
Solvent : n-hexane Temperature : 303 K
C Lf Vf /10-7 ππππi CE Z /105 Va /10-5 LJP
M Ao m3 atm kJ mol-1 kg-2 s-1 m3
0.001 0.7 5.2 2349 32.3 6.7 4.7 4.5
0.002 0.7 5.3 2341 32.2 6.7 4.6 4.7
0.003 0.7 5.2 2346 32.3 6.7 4.6 4.6
0.004 0.8 5.2 2347 32.4 6.7 4.7 4.5
0.005 0.8 5.2 2347 32.4 6.6 4.7 4.4
0.006 0.8 5.2 2344 32.3 6.7 4.7 4.4
0.007 0.8 5.1 2352 32.5 6.6 4.7 4.4
0.008 0.7 5.2 2356 32.4 6.7 4.7 4.4
0.009 0.8 5.2 2349 32.4 6.7 4.7 4.4
0.010 0.8 5.2 2345 32.4 6.6 4.7 4.4
Plots : Fig. 5.4 πi vs Concentration;
Fig. 5.5 CE vs Concentration;
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136
TABLE 5.3
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ),
ABSORPTION COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU)
AND RELAXATION TIME (ττττ) AT VARIOUS CONCENTRATIONS OF IODINE - PARA XYLENE SYSTEM
Solvent : n-hexane Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 ττττ /10-13
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 s
0.001 1050.4 636.4 3.32 1.42 11.8 -15.0 6.3
0.002 1052.8 636.6 3.32 1.42 11.7 -10.7 6.3
0.003 1053.1 636.9 3.30 1.42 11.7 -10.3 6.2
0.004 1053.5 635.9 3.30 1.42 11.7 -9.7 6.2
0.005 1054.3 635.6 3.29 1.42 11.6 -8.3 6.2
0.006 1053.5 637.1 3.30 1.41 11.7 -10.0 6.2
0.007 1054.1 634.9 3.28 1.42 11.6 -9.0 6.2
0.008 1053.1 638.2 3.30 1.41 11.6 -11.1 6.2
0.009 1055.4 635.8 3.31 1.41 11.6 -6.9 6.2
0.010 1057.2 635.4 3.31 1.41 11.6 -3.7 6.2
Plots : Fig. 5.1 U vs Concentration; Fig. 5.3 χU vs Concentration;
Fig. 5.2 κ vs Concentration;
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137
TABLE 5.4
FREE LENGTH (Lf), FREE VOLUME (Vf), INTERNAL PRESSURE (ππππi), COHESSIVE ENERGY (CE),
ACOUSTICAL IMPEDANCE (Z), AVAILABLE VOLUME (Va) AND LENARD JONES POTENTIAL (LJP),
AT VARIOUS CONCENTRATIONS OF IODINE - PARA XYLENE SYSTEM
Solvent : n-hexane Temperature : 303 K
C Lf Vf /10-7 ππππi CE Z /105 Va /10-5 LJP
M Ao m3 atm kJ mol-1 kg-2 s-1 m3
0.001 0.7 5.1 2370 32.5 6.7 4.7 4.5
0.002 0.7 5.1 2366 32.5 6.7 4.6 4.5
0.003 0.7 5.2 2360 32.4 6.7 4.6 4.6
0.004 0.7 5.2 2357 32.4 6.7 4.6 4.6
0.005 0.7 5.2 2350 32.3 6.7 4.6 4.6
0.006 0.7 5.2 2358 32.4 6.7 4.6 4.6
0.007 0.7 5.2 2344 32.3 6.7 4.6 4.6
0.008 0.7 5.2 2358 32.3 6.7 4.6 4.6
0.009 0.7 5.2 2352 32.4 6.7 4.6 4.6
0.010 0.7 5.2 2350 32.4 6.7 4.6 4.7
Plots : Fig. 5.4 πi vs Concentration;
Fig. 5.5 CE vs Concentration;
Page 138
138
TABLE 5.5
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ),
ABSORPTION COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU)
AND RELAXATION TIME (ττττ) AT VARIOUS CONCENTRATIONS OF IODINE - META XYLENE SYSTEM
Solvent : n-hexane Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 ττττ /10-13
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 s
0.001 1057.2 636.8 3.37 1.41 11.8 -2.2 6.3
0.002 1061.2 636.8 3.37 1.39 11.7 5.2 6.3
0.003 1057.8 637.6 3.36 1.40 11.7 -1.4 6.3
0.004 1058.5 636.1 3.36 1.40 11.7 -0.2 6.3
0.005 1058.3 635.8 3.36 1.40 11.7 -0.8 6.3
0.006 1058.1 637.0 3.36 1.40 11.7 -1.3 6.3
0.007 1056.1 635.4 3.34 1.41 11.7 -5.2 6.3
0.008 1052.4 638.8 3.38 1.41 11.9 -12.3 6.4
0.009 1052.5 636.4 3.37 1.42 11.9 -12.3 6.4
0.010 1050.8 635.4 3.36 1.43 12.0 -15.6 6.4
Plots : Fig. 5.1 U vs Concentration; Fig. 5.3 χU vs Concentration;
Fig. 5.2 κ vs Concentration;
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TABLE 5.6
FREE LENGTH (Lf), FREE VOLUME (Vf), INTERNAL PRESSURE (ππππi), COHESSIVE ENERGY (CE),
ACOUSTICAL IMPEDANCE (Z), AVAILABLE VOLUME (Va) AND LENARD JONES POTENTIAL (LJP),
AT VARIOUS CONCENTRATIONS OF IODINE - META XYLENE SYSTEM
Solvent : n-hexane Temperature : 303 K
C Lf Vf /10-7 ππππi CE Z /105 Va /10-5 LJP
M Ao m3 atm kJ mol-1 kg-2 s-1 m3
0.001 0.7 5.0 2382 32.7 6.7 4.6 4.7
0.002 0.7 5.0 2377 32.6 6.8 4.6 4.8
0.003 0.7 5.0 2379 32.6 6.7 4.6 4.7
0.004 0.7 5.1 2372 32.6 6.7 4.6 4.7
0.005 0.7 5.1 2372 32.6 6.7 4.6 4.7
0.006 0.7 5.1 2374 32.6 6.7 4.6 4.7
0.007 0.7 5.1 2364 32.5 6.7 4.6 4.7
0.008 0.7 5.0 2388 32.7 6.7 4.6 4.5
0.009 0.7 5.0 2378 32.7 6.7 4.6 4.5
0.010 0.7 5.0 2376 32.7 6.7 4.7 4.5
Plots : Fig. 5.4 πi vs Concentration;
Fig. 5.5 CE vs Concentration;
Page 140
140
TABLE 5.7
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ),
ABSORPTION COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU)
AND RELAXATION TIME (ττττ) AT VARIOUS CONCENTRATIONS OF IODINE - ORTHO XYLENE SYSTEM
Solvent : n-hexane Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 ττττ /10-13
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 s
0.001 1058.0 637.5 3.36 1.40 11.7 -0.7 6.3
0.002 1058.8 637.2 3.35 1.40 11.6 0.6 6.2
0.003 1063.4 637.1 3.36 1.39 11.5 9.2 6.2
0.004 1059.2 637.1 3.35 1.40 11.6 1.1 6.3
0.005 1056.0 637.8 3.37 1.41 11.8 -5.1 6.3
0.006 1058.0 636.5 3.38 1.40 11.8 -1.5 6.3
0.007 1060.0 636.7 3.38 1.40 11.7 2.1 6.3
0.008 1061.2 637.1 3.38 1.39 11.7 4.2 6.3
0.009 1062.4 635.9 3.36 1.39 11.6 6.3 6.2
0.010 1058.8 638.7 3.39 1.40 11.7 -0.7 6.3
Plots : Fig. 5.1 U vs Concentration; Fig. 5.3 χU vs Concentration;
Fig. 5.2 κ vs Concentration;
Page 141
141
TABLE 5.8
FREE LENGTH (Lf), FREE VOLUME (Vf), INTERNAL PRESSURE (ππππi), COHESSIVE ENERGY (CE),
ACOUSTICAL IMPEDANCE (Z), AVAILABLE VOLUME (Va) AND LENARD JONES POTENTIAL (LJP),
AT VARIOUS CONCENTRATIONS OF IODINE - ORTHO XYLENE SYSTEM
Solvent : n-hexane Temperature : 303 K
C Lf Vf /10-7 ππππi CE Z /105 Va /10-5 LJP
M Ao m3 atm kJ mol-1 kg-2 s-1 m3
0.001 0.7 5.1 2378 32.6 6.7 4.6 4.7
0.002 0.7 5.1 2372 32.5 6.7 4.6 4.7
0.003 0.7 5.1 2370 32.5 6.8 4.5 4.9
0.004 0.7 5.1 2371 32.5 6.7 4.6 4.8
0.005 0.7 5.0 2381 32.6 6.7 4.6 4.6
0.006 0.7 5.0 2381 32.7 6.7 4.6 4.7
0.007 0.7 5.0 2376 32.6 6.7 4.6 4.8
0.008 0.7 5.0 2377 32.6 6.8 4.6 4.8
0.009 0.7 5.1 2365 32.6 6.8 4.6 4.9
0.010 0.7 5.0 2383 32.7 6.8 4.6 4.7
Plots : Fig. 5.4 πi vs Concentration;
Fig. 5.5 CE vs Concentration;
Page 142
142
TABLE 5.9
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ),
ABSORPTION COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU)
AND RELAXATION TIME (ττττ) AT VARIOUS CONCENTRATIONS OF IODINE - TOLUENE SYSTEM
Solvent : n-hexane Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 ττττ /10-13
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 s
0.001 1059.6 637.3 3.41 1.40 11.8 2.3 6.3
0.002 1061.7 636.4 3.40 1.39 11.7 6.1 6.3
0.003 1061.2 637.7 3.38 1.39 11.6 5.0 6.3
0.004 1060.1 637.5 3.37 1.40 11.7 2.8 6.3
0.005 1061.5 635.6 3.35 1.40 11.6 5.3 6.2
0.006 1064.9 638.2 3.36 1.38 11.5 11.6 6.2
0.007 1066.2 637.4 3.37 1.38 11.5 13.9 6.2
0.008 1064.5 637.1 3.36 1.39 11.5 10.5 6.2
0.009 1062.4 638.6 3.38 1.39 11.6 6.4 6.3
0.010 1062.6 637.2 3.36 1.39 11.6 6.6 6.2
Plots : Fig. 5.1 U vs Concentration; Fig. 5.3 χU vs Concentration;
Fig. 5.2 κ vs Concentration;
Page 143
143
TABLE 5.10
FREE LENGTH (Lf), FREE VOLUME (Vf), INTERNAL PRESSURE (ππππi), COHESSIVE ENERGY (CE),
ACOUSTICAL IMPEDANCE (Z), AVAILABLE VOLUME (Va) AND LENARD JONES POTENTIAL (LJP),
AT VARIOUS CONCENTRATIONS OF IODINE - TOLUENE SYSTEM
Solvent : n-hexane Temperature : 303 K
C Lf Vf /10-7 ππππi CE Z /105 Va /10-5 LJP
M Ao m3 atm kJ mol-1 kg-2 s-1 m3
0.001 0.7 5.0 2393 32.8 6.8 4.6 4.8
0.002 0.7 5.0 2386 32.7 6.8 4.6 4.8
0.003 0.7 5.0 2380 32.6 6.8 4.6 4.8
0.004 0.7 5.1 2377 32.6 6.8 4.6 4.8
0.005 0.7 5.1 2363 32.5 6.7 4.6 4.8
0.006 0.7 5.1 2370 32.5 6.8 4.5 4.9
0.007 0.7 5.1 2369 32.5 6.8 4.5 5.0
0.008 0.7 5.1 2364 32.5 6.8 4.5 4.9
0.009 0.7 5.1 2378 32.6 6.8 4.5 4.9
0.010 0.7 5.1 2366 32.5 6.8 4.6 4.9
Plots : Fig. 5.4 πi vs Concentration;
Fig. 5.5 CE vs Concentration;
Page 144
144
TABLE 5.11
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ),
ABSORPTION COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU)
AND RELAXATION TIME (ττττ) AT VARIOUS CONCENTRATIONS OF IODINE - BENZENE SYSTEM
Solvent : n-hexane Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 ττττ /10-13
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 s
0.001 1058.1 639.4 3.41 1.40 11.8 -0.5 6.3
0.002 1059.2 638.2 3.40 1.40 11.8 1.4 6.3
0.003 1058.4 638.7 3.40 1.40 11.8 -0.3 6.3
0.004 1058.9 637.8 3.39 1.40 11.8 0.5 6.3
0.005 1061.1 637.9 3.37 1.39 11.6 4.5 6.3
0.006 1064.4 639.8 3.37 1.38 11.5 10.6 6.2
0.007 1059.7 639.7 3.40 1.39 11.8 1.6 6.3
0.008 1067.7 640.1 3.36 1.37 11.3 16.6 6.1
0.009 1068.1 638.7 3.36 1.37 11.4 17.2 6.1
0.010 1068.0 638.7 3.37 1.37 11.4 16.9 6.2
Plots : Fig. 5.1 U vs Concentration; Fig. 5.3 χU vs Concentration;
Fig. 5.2 κ vs Concentration;
Page 145
145
TABLE 5.12
FREE LENGTH (Lf), FREE VOLUME (Vf), INTERNAL PRESSURE (ππππi), COHESSIVE ENERGY (CE),
ACOUSTICAL IMPEDANCE (Z), AVAILABLE VOLUME (Va) AND LENARD JONES POTENTIAL (LJP),
AT VARIOUS CONCENTRATIONS OF IODINE - BENZENE SYSTEM
Solvent : n-hexane Temperature : 303 K
C Lf Vf /10-7 ππππi CE Z /105 Va /10-5 LJP
M Ao m3 atm kJ mol-1 kg-2 s-1 m3
0.001 0.7 4.9 2401 32.8 6.8 4.6 4.7
0.002 0.7 5.0 2393 32.8 6.8 4.6 4.8
0.003 0.7 5.0 2394 32.7 6.8 4.6 4.7
0.004 0.7 5.0 2386 32.7 6.8 4.6 4.7
0.005 0.7 5.1 2378 32.6 6.8 4.6 4.8
0.006 0.7 5.1 2377 32.5 6.8 4.5 4.9
0.007 0.7 5.0 2394 32.7 6.8 4.6 4.8
0.008 0.7 5.1 2370 32.4 6.8 4.5 5.0
0.009 0.7 5.1 2366 32.4 6.8 4.5 5.0
0.010 0.7 5.1 2368 32.4 6.8 4.5 5.0
Plots : Fig. 5.4 πi vs Concentration;
Fig. 5.5 CE vs Concentration;
Page 146
146
TABLE 5.13
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ),
ABSORPTION COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU)
AND RELAXATION TIME (ττττ) AT VARIOUS CONCENTRATIONS OF IODINE - ANTHRACENE SYSTEM
Solvent : n-hexane Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 ττττ /10-13
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 s
0.001 1060.3 638.3 3.37 1.39 11.6 3.4 6.3
0.002 1060.0 639.1 3.39 1.39 11.7 2.4 6.3
0.003 1060.2 637.3 3.39 1.40 11.7 2.4 6.3
0.004 1056.9 636.5 3.41 1.41 11.9 -4.2 6.4
0.005 1061.2 638.1 3.41 1.39 11.8 3.5 6.3
0.006 1060.3 636.1 3.39 1.40 11.8 1.4 6.3
0.007 1059.2 636.9 3.38 1.40 11.8 -1.0 6.3
0.008 1058.0 635.4 3.38 1.41 11.8 -3.7 6.3
0.009 1061.6 639.3 3.39 1.39 11.6 2.7 6.3
0.010 1060.8 639.5 3.41 1.39 11.8 0.8 6.3
Plots : Fig. 5.6 U vs Concentration; Fig. 5.8 χU vs Concentration;
Fig. 5.7 κ vs Concentration;
Page 147
147
TABLE 5.14
FREE LENGTH (Lf), FREE VOLUME (Vf), INTERNAL PRESSURE (ππππi), COHESSIVE ENERGY (CE),
ACOUSTICAL IMPEDANCE (Z), AVAILABLE VOLUME (Va) AND LENARD JONES POTENTIAL (LJP),
AT VARIOUS CONCENTRATIONS OF IODINE - ANTHRACENE SYSTEM
Solvent : n-hexane Temperature : 303 K
C Lf Vf /10-7 ππππi CE Z /105 Va /10-5 LJP
M Ao m3 atm kJ mol-1 kg-2 s-1 m3
0.001 0.7 5.0 2382 32.6 6.8 4.6 4.8
0.002 0.7 5.0 2391 32.7 6.8 4.6 4.8
0.003 0.7 5.0 2383 32.7 6.8 4.6 4.8
0.004 0.7 4.9 2393 32.9 6.7 4.6 4.7
0.005 0.7 5.0 2391 32.8 6.8 4.6 4.8
0.006 0.7 5.0 2377 32.7 6.7 4.6 4.8
0.007 0.7 5.0 2377 32.7 6.7 4.6 4.8
0.008 0.7 5.0 2371 32.7 6.7 4.6 4.7
0.009 0.7 5.0 2380 32.6 6.8 4.6 4.8
0.010 0.7 5.0 2389 32.7 6.8 4.6 4.8
Plots : Fig. 5.9 πi vs Concentration;
Fig. 5.10 CE vs Concentration;
Page 148
148
TABLE 5.15
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ),
ABSORPTION COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU)
AND RELAXATION TIME (ττττ) AT VARIOUS CONCENTRATIONS OF IODINE - BIPHENYL SYSTEM
Solvent : n-hexane Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 ττττ /10-13
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 s
0.001 1088.1 679.7 3.78 1.24 11.3 56.9 6.3
0.002 1086.2 679.6 3.74 1.25 11.3 53.0 6.2
0.003 1084.4 679.3 3.74 1.25 11.4 49.2 6.2
0.004 1082.0 677.1 3.75 1.26 11.5 44.4 6.3
0.005 1079.6 675.1 3.67 1.27 11.4 39.5 6.2
0.006 1077.3 674.6 3.65 1.28 11.4 34.9 6.2
0.007 1075.3 665.7 3.52 1.30 11.2 30.8 6.1
0.008 1072.8 666.7 3.55 1.30 11.3 25.8 6.2
0.009 1070.1 667.7 3.56 1.31 11.4 20.4 6.2
0.010 1065.7 668.0 3.54 1.32 11.5 11.8 6.2
Plots : Fig. 5.6 U vs Concentration; Fig. 5.8 χU vs Concentration;
Fig. 5.7 κ vs Concentration;
Page 149
149
TABLE 5.16
FREE LENGTH (Lf), FREE VOLUME (Vf), INTERNAL PRESSURE (ππππi), COHESSIVE ENERGY (CE),
ACOUSTICAL IMPEDANCE (Z), AVAILABLE VOLUME (Va) AND LENARD JONES POTENTIAL (LJP),
AT VARIOUS CONCENTRATIONS OF IODINE - BIPHENYL SYSTEM
Solvent : n-hexane Temperature : 303 K
C Lf Vf /10-7 ππππi CE Z /105 Va /10-5 LJP
M Ao m3 atm kJ mol-1 kg-2 s-1 m3
0.001 0.7 4.4 2596 33.3 7.4 4.1 5.8
0.002 0.7 4.5 2585 33.2 7.4 4.1 5.7
0.003 0.7 4.5 2585 33.3 7.4 4.1 5.6
0.004 0.7 4.4 2583 33.4 7.3 4.1 5.5
0.005 0.7 4.6 2553 33.1 7.3 4.2 5.4
0.006 0.7 4.6 2547 33.0 7.3 4.2 5.4
0.007 0.7 4.8 2481 32.6 7.2 4.3 5.3
0.008 0.7 4.8 2496 32.8 7.2 4.3 5.2
0.009 0.7 4.7 2501 32.8 7.1 4.3 5.1
0.010 0.7 4.8 2499 32.8 7.1 4.3 5.0
Plots : Fig. 5.9 πi vs Concentration;
Fig. 5.10 CE vs Concentration;
Page 150
150
TABLE 5.17
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ),
ABSORPTION COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU)
AND RELAXATION TIME (ττττ) AT VARIOUS CONCENTRATIONS OF IODINE - NAPHTHALENE SYSTEM
Solvent : n-hexane Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 ττττ /10-13
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 s
0.001 1058.8 664.1 3.51 1.34 11.7 0.7 6.3
0.002 1064.3 665.2 3.53 1.33 11.6 10.8 6.3
0.003 1064.7 665.6 3.52 1.33 11.5 11.3 6.2
0.004 1064.4 665.8 3.53 1.33 11.6 10.4 6.2
0.005 1064.9 665.9 3.51 1.32 11.5 11.1 6.2
0.006 1064.8 666.0 3.51 1.32 11.5 10.7 6.2
0.007 1065.1 666.1 3.50 1.32 11.4 10.9 6.2
0.008 1061.2 666.7 3.49 1.33 11.5 3.3 6.2
0.009 1065.8 667.4 3.52 1.32 11.5 11.7 6.2
0.010 1063.2 666.6 3.51 1.33 11.5 6.5 6.2
Plots : Fig. 5.6 U vs Concentration; Fig. 5.8 χU vs Concentration;
Fig. 5.7 κ vs Concentration;
Page 151
151
TABLE 5.18
FREE LENGTH (Lf), FREE VOLUME (Vf), INTERNAL PRESSURE (ππππi), COHESSIVE ENERGY (CE),
ACOUSTICAL IMPEDANCE (Z), AVAILABLE VOLUME (Va) AND LENARD JONES POTENTIAL (LJP),
AT VARIOUS CONCENTRATIONS OF IODINE - NAPHTHALENE SYSTEM
Solvent : n-hexane Temperature : 303 K
C Lf Vf /10-7 ππππi CE Z /105 Va /10-5 LJP
M Ao m3 atm kJ mol-1 kg-2 s-1 m3
0.001 0.7 4.7 2497 32.8 7.0 4.4 4.7
0.002 0.7 4.7 2501 32.8 7.1 4.3 4.9
0.003 0.7 4.8 2496 32.8 7.1 4.3 4.9
0.004 0.7 4.7 2499 32.8 7.1 4.3 4.9
0.005 0.7 4.8 2492 32.7 7.1 4.3 4.9
0.006 0.7 4.8 2492 32.7 7.1 4.3 4.9
0.007 0.7 4.8 2488 32.7 7.1 4.3 4.9
0.008 0.7 4.8 2489 32.7 7.1 4.4 4.8
0.009 0.7 4.8 2494 32.7 7.1 4.3 5.0
0.010 0.7 4.8 2489 32.7 7.1 4.4 4.9
Plots : Fig. 5.9 πi vs Concentration;
Fig. 5.10 CE vs Concentration;
Page 152
152
TABLE 5.19
MEAN VALUES OF GIBB'S FREE ENERGY OF FORMATION (∆G), MEAN VALUES OF
GIBB'S FREE ENERGY OF ACTIVATION (∆G#) AND MEAN VALUES FORMATION CONSTANT (K)
OF HYDROCARBON COMPOUNDS WITH IODINE IN n-HEXANE SOLUTIONS
Solvent : n-hexane Temperature : 303 K
∆G ∆G# K
Donor kJ mol-1 kJ mol-1 dm-3 mol-1
Mesitylene -9.5 3.8 44.9
p-Xylene -9.5 3.8 43.0
m-Xylene -9.1 3.8 37.6
o-Xylene -8.8 3.8 32.7
Toluene -8.5 3.8 28.7
Benzene -8.2 3.8 25.5
Anthracene -10.2 3.8 58.3
Biphenyl -9.3 3.8 41.1
Naphthalene -8.6 3.8 30.7
Page 153
153
TABLE 5.20
ADIABATIC COMPRESSIBILITY (κκκκ) AND FREE LENGTH (Lf) OF PURE COMPONENTS
Temperature : 303 K
component κ /κ /κ /κ /10-9 Lf
kg-1ms2 Ao
n-Hexane 1.35 0.73
Mesitylene 0.67 0.51
p-Xylene 0.66 0.51
m-Xylene 0.69 0.52
o-Xylene 0.65 0.51
Toluene 0.69 0.52
Benzene 0.68 0.52
Anthracene 0.16 0.41
Biphenyl 0.42 0.25
Naphthalene 0.27 0.33
Page 154
Fig. 5.1 Plots of Ultrasonic velocity vs Concentration
1045
1050
1055
1060
1065
1070
0.000 0.002 0.004 0.006 0.008 0.010 0.012
Concentration, M
U,
m s
-1
IO-MST IO-PXLIO-MXL IO-OXLIO-BZ IO-TL
Solvent : n-hexane Temperature : 303 K
Fig. 5.2 Plots of Adiabatic compressibility vs Concentration
1.36
1.37
1.38
1.39
1.40
1.41
1.42
1.43
1.44
1.45
0.000 0.002 0.004 0.006 0.008 0.010 0.012
Concentration, M
κκ κκ /
10
-9,
kg
-1m
s2
IO-MST IO-PXLIO-MXL IO-OXLIO-BZ IO-TL
Solvent : n-hexane Temperature : 303 K
Page 155
155
Fig. 5.3 Plots of Molecular interaction parameter vs Concentration
-25.0
-20.0
-15.0
-10.0
-5.0
0.0
5.0
10.0
15.0
20.0
0.000 0.002 0.004 0.006 0.008 0.010 0.012
Concentration, M
χχ χχU/1
0-3
, m
s-1
IO-MST IO-PXLIO-MXL IO-OXLIO-BZ IO-TL
Solvent : n-hexane Temperature : 303 K
Fig. 5.4 Plots of Internal pressure vs Concentration
2330
2340
2350
2360
2370
2380
2390
2400
2410
0.000 0.002 0.004 0.006 0.008 0.010 0.012
Concentration, M
ππ ππi, a
tm
IO-MST IO-PXL IO-MXLIO-OXL IO-BZ IO-TL
Solvent : n-hexane Temperature : 303 K
Page 156
156
Fig. 5.5 Plots of Cohessive energy vs Concentration
32.1
32.2
32.3
32.4
32.5
32.6
32.7
32.8
32.9
0.000 0.002 0.004 0.006 0.008 0.010 0.012
Concentration, M
CE
, kJ m
ol-1
IO-MST IO-PXLIO-MXL IO-OXLIO-BZ IO-TL
Solvent : n-hexane Temperature : 303 K
Fig. 5.6 Plots of Ultrasonic velocity vs Concentration
1055
1060
1065
1070
1075
1080
1085
1090
0.000 0.002 0.004 0.006 0.008 0.010 0.012
Concentration, M
U,
ms
-1
IO-ANTIO-BIPIO-NAP
Solvent : n-hexane Temperature : 303 K
Page 157
157
Fig. 5.7 Plots of Adiabatic compressibility vs Concentration
1.19
1.31
1.43
0.000 0.002 0.004 0.006 0.008 0.010 0.012
Concentration, M
κκ κκ /
10
-9,
kg
-1m
s2
IO-ANTIO-BIPIO-NAP
Solvent : n-hexane Temperature : 303 K
Fig. 5.8 Plots of Molecular interaction parameter vs Concentration
-10
0
10
20
30
40
50
60
0.000 0.002 0.004 0.006 0.008 0.010 0.012
Concentration, M
χχ χχU/1
0-3
, m
s-1
IO-ANTIO-BIPIO-NAP
Solvent : n-hexane Temperature : 303 K
Page 158
158
Fig. 5.9 Plots of Internal pressure vs Concentration
2350
2400
2450
2500
2550
2600
0.000 0.002 0.004 0.006 0.008 0.010 0.012
Concentration, M
ππ ππi, a
tm
IO-ANTIO-BIPIO-NAP
Solvent : n-hexane Temperature : 303 K
Fig. 5.10 Plots of Cohessive energy vs Concentration
32.4
32.8
33.2
33.6
0.000 0.002 0.004 0.006 0.008 0.010
Concentration, M
CE
, kJ m
ol-1
IO-ANTIO-BIPIO-NAP
Solvent : n-hexane Temperature : 303 K
Page 160
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CHAPTER – 6
DETERMINATION OF STABILITY CONSTANTS OF CHARGE TRANSFER COMPLEXES BETWEEN IODINE MONOCHLORIDE AND CERTAIN AROMATIC
HYDROCARBONS IN n-HEXANE
6.1. INTRODUCTION
Ultrasound has been used to detect donor-acceptor complexes in
solution1,2. Prakash et al3 have determined stability constants of charge
trasfer complexes by ultrasonic methods. Jaya Santhi2 used ultrasound to
determine the stability constants of donor-acceptor complexes between
carbonyl compounds and tetrachloroethylene in n-hexane solution.
Kannappan et al have investigated the interactions in charge transfer
complexes of chloroform and carboxyl compounds in sloution.
The donor-acceptor complex formation is biologically important. Oxygen
transfer in blood involves reversible complexation between haeme and
oxygen. It has been suggested that the carcinogenic activity of certain
chemicals is due to the complexes formed between these chemicals and DNA
and consequent occurrence of DNA repairs result in the formation of
cancerous cell4,5. Bacteria obtain energy to grow by transforming electrons
from donor to acceptor. These microorganisms get energy through their
cellular machinery. The complexation reactions are of interest not only
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because they allow organisms to obtain energy, but also because they involve
in the natural biodegradation of organic contaminants6,7. Kannappan and
Kothai8-11 have made investigation on charge transfer complexes formed
using iodine as acceptor.
Iodine monochloride is an important interhalogen compound. It is
mainly used as iodinating agent and in the determination of iodine value of oil
under the trade name Wijs’ solution. It is a polar compound and iodine is the
positive end of the dipole. It acts as a Lewis acid and forms additional
products with olefins12. It is a dark brown liquid and it is highly corrosive,
although it is neither a potential carcinogen nor a suspected carcinogen. It
was once used in small doses to cure pregnancy goitre but as it was proved to
be fatal in few cases, it was abandoned13. It can be used to synthesise iodo
compounds from alkenes and it is also used as an iodinating agent for
aromatic compounds, in which iodine monochloride acts as an electrophile.
In both the addition and substitution reactions, it is suggested that a
transient intermediate, namely, π complex is formed. The formation of such π
complexes has been detected in typical cases14. Recently, Al Mokhtar
Lambabhi et al have detected several charge transfer complexes formed
between iodine monochloride and carbonyl compounds by ultraviolet
spectroscopic method15. Equilibrium constants and Gibb’s energy changes for
the formation of 1:1 charge transfer complexes were also determined with a
view to compare the basicity of the carbonyl compounds. They also found that
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the basicity of carbonyl compounds towards iodine monochloride is enhanced
with respect to that exhibited towards iodine. As a consequence, the
substituent’s effect on the Gibb’s energy is twice larger in iodine
monochloride than in iodine complexes. In the previous chapter, the
formation constants of iodine with aromatic hydrocarbons are reported. In
order to compare those results, the formation constants for charge transfer
complexes of iodine monochloride with nine aromatic hydrocarbons are
determined and the results obtained in their ultrasonic studies are reported
in this chapter and discussed.
The acoustical parameters such as adiabatic compressibility (κ),
absorption coefficient (α/f2), molecular interaction parameter (χU), relaxation
time (τ), free length (Lf), internal pressure (πi), cohesive energy (CE), acoustical
impedance (Z), Lenard Jones Potential (LJP) and Gibb’s free energy of
activation (∆G#) are calculated at various concentrations. The interaction
between the donor and acceptor molecules has been studied from the
variation of acoustical parameters with concentration. The stability constant
(K) values are calculated for all the nine complexes in n-hexane at
303 K.
6.2. RESULTS AND DISCUSSION
The acoustical parameters along with measured ultrasonic velocities,
densities and viscosities for six monocyclic aromatic hydrocarbons and three
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polynuclear hydrocarbons at 303 K are given in Tables 6.1 – 6.18. These data
are discussed in the light of molecular interaction and complexation between
the components. Their corresponding plots are given in Figs. 6.1 – 6.10.
The ultrasonic velocity (U) increases slightly with concentration in the
case of all systems except in o-xylene-iodine monochloride, anthracene-iodine
monochloride and benzene-iodine monochloride systems. Further, there is a
characteristic concentration for each system at which the ultrasonic velocity
is a maximum. Even in the three systems in which ultrasonic velocity
decreases initially, there is an increase in velocity at a particular
concentration. These observations establish the formation of charge transfer
complexes between iodine monochloride and the aromatic hydrocarbons. This
is also suggested by the slight increase in density and viscosity at these
concentrations. Plots of ultrasonic velocity vs concentration for the
monocyclic systems are given in Fig. 6.1 while Fig. 6.6 contains similar plots
for polycyclic systems.
Adiabatic compressibility (κ) values are computed from ultrasonic
velocity and density for all the systems and are given in Tables 6.1 – 6.18.
Plots of adiabatic compressibility vs concentration are presented in Fig. 6.2
for monocyclic aromatic systems while similar plots for polycyclic systems are
given in Fig. 6.7. It may be pointed out here that whether adiabatic
compressibility increases or decreases at low concentration, the value is
found to be a minimum at the same concentration at which the ultrasonic
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velocity, density and viscosity values are at maximum. This trend in adiabatic
compressibility in all the nine systems suggests that complexation between
iodine monochloride and aromatic hydrocarbon is a maximum at a specific
concentration which is characteristic of the system.
Thus, minimum values of stability constant are observed for systems
containing benzene derivatives in the concentration range 0.003 M and
0.006 M which indicate the maximum complexation in this concentration
range. In the case of anthracene, the adiabatic compressibility value
decreases between 0.008 M and 0.01 M. This shows maximum complexation
at this concentration for anthracene system. A similar trend is seen in the
case of biphenyl and naphthalene also. The values are listed in Tables 6.13,
6.15 and 6.17; the corresponding plots are given in Fig. 6.7.
The molecular interaction parameter (χU) is indicative of the extent of
deviation of ultrasonic velocity from ideal behaviour. These values can be
used to assess the strength of molecular attraction between the donor and
acceptor in non-polar medium like n-hexane. Tables 6.1, 6.3, 6.5, 6.7, 6.9
and 6.11 give the values of molecular interaction parameter, and the
corresponding plots are given in Fig. 6.3 for the six monocyclic hydrocarbons.
These molecular interaction parameter values vary with concentration
indicating that the extent of deviation from ideal behaviour and the extent of
complexation are both concentration dependent. For monocyclic systems, the
molecular interaction parameter values are positive except that for benzene.
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The molecular interaction parameter values are generally positive, but
negative in the concentration from 0.003 M to 0.007 M in the case of
polynuclear aromatic hydrocarbons except for anthracene system. This
positive value indicates that iodine monochloride-biphenyl and iodine
monochloride-naphthalene complexes may be less stable than that of iodine
monochloride-anthracene complex. The plots of molecular interaction
parameter vs concentration for polycyclic systems are presented in Fig. 6.8.
The absorption coefficient (α/f2) and relaxation time (τ) values are
almost constant for a given system, indicating that they are characteristic
properties of the complex. These values are given in Tables 6.1, 6.3, 6.5, 6.7,
6.9, 6.11, 6.13, 6.15 and 6.17. However, the slight difference in absorption
coefficient values for different systems is indicative of different strength in
molecular interactions between the donor and acceptor in systems studied.
The free length (Lf) values are given in Tables 6.2, 6.4, 6.6, 6.8, 6.10,
6.12, 6.14, 6.16 and 6.18. These values are calculated from ultrasonic
velocity and viscosity values and they are used to detect and analyze the
intermolecular attraction between the molecules of the components in the
system. It may be pointed out here that the free length values are almost
constant for each system and independent of concentration. Thus, the iodine
monochloride molecules form similar type of complexes with the aromatic
hydrocarbon. It may be possible that the positive end of the dipole in iodine
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166
monochloride may attract the π-electron cloud and the molecular axis of
iodine monochloride may be perpendicular to the plane of the aromatic
hydrocarbon molecule. The free length values are slightly greater than those
for pure components, indicating the iodine monochloride-aromatic
hydrocarbon complex formation.
The internal pressure (πi) is a measure of binding forces between the
solute and solvent molecules. The internal pressure values are calculated
from the values of ultrasonic velocity, density and viscosity. The internal
pressure values for the six monocyclic hydrocarbons are presented in Tables
6.1, 6.3, 6.5, 6.7, 6.9, and 6.11. The corresponding plots are given in Fig. 6.4.
The internal pressure values are maximum at concentration range 0.003 M -
0.004 M indicating maximum complexation in this concentration range. The
variation of internal pressure with concentration for polynuclear aromatic
hydrocarbons indicates that the complexation is maximum at higher values of
concentration. Tables 6.13, 6.15 and 6.17 contain the values of internal
pressure for the polynuclear aromatic hydrocarbon stystems. The
corresponding plots are given in Fig. 6.9.
The cohesive energy (CE) in liquid mixtures indicates the forces of
attraction between the component molecules. The values of cohesive energy
for all the nine systems are given in Tables 6.2, 6.4, 6.6, 6.8, 6.10, 6.12, 6.14,
6.16 and 6.18. The corresponding plots are given in Figs. 6.5 and 6.10. The
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cohesive energy value is maximum at a specific concentration which is
characteristic of the system.
The values of acoustic impedance (Z), free volume (Vf) and available
volume (Va) are presented in Tables 6.2, 6.4, 6.6, 6.8, 6.10, 6.12, 6.14, 6.16
and 6.18. It is found that the acoustic impedance, free volume and available
volume do not change significantly in these nine systems. Thus, complexation
between iodine monochloride and aromatic hydrocarbons does not influence
acoustic impedance, available volume and free volume values. This indicates
that there is formation of similar complexes in these systems.
The formation constants (K) can be used to compare stabilities of the
charge transfer complexes. In all the nine systems, the donor is the aromatic
hydrocarbon molecule which is a π-electron donor and so it is expected that
the extension of conjugation of the π-electron system should increase the
stability constant values. The mean values of formation constants are
calculated and presented in Table 6.19. The formation constant is almost a
constant for a particular system, indicating that it is characteristic of the
system and independent of concentration. From the values of stability
constant, the stability of charge transfer complexes are found to be in the
order
ICl-mesitylene > ICl -p-xylene > ICl -m-xylene >
ICl -o-xylene > ICl-toluene > ICl -benzene
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In the case of monocyclic aromatic hydrocarbons, and in polycyclic
aromatic systems, it is in the order
ICl -anthracene > ICl -biphenyl > ICl -naphthalene
This trend can be explained as follows. In toluene molecule, the presence of
electron releasing methyl group enhances the basicity of the donor molecule.
Hence, the stability constant for iodine monochloride-toluene complex is
slightly greater than that of iodine monochloride-benzene charge transfer
complex. This is also supported by the higher values for charge transfer
complexes of iodine monochloride and xylenes, which contain two methyl
substituents. Among xylenes, p-xylene complex is more stable than m-xylene
complex which is slightly more stable than o-xylene complex. This may be
due to steric reason. Of the three charge transfer complexes of iodine
monochloride and polycyclic aromatic hydrocarbons, iodine monochloride-
anthracene complex is the most stable. This may be due to the maximum
π-electron density in anthracene. Biphenyl with twelve π electrons has greater
π-electron density than naphthalene with only ten π electrons. Hence, the
formation constant of iodine monochloride-biphenyl complex is greater than
that of iodine monochloride-naphthalene complex.
It may be of interest to compare the formation constants of iodine-
aromatic hydrocarbons with those of iodine monochloride-aromatic
hydrocarbon complexes. It is found that the order of stability is in the same
order among the nine systems for both iodine and iodine monochloride as
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acceptors. Further, the complexes formed between iodine monochloride and
aromatic hydrocarbons are more stable than the complexes formed between
iodine and the same donors. Similar observations were made by Al Mokhtar
Lambabhi and coworkers15 in the study of complexes of carbonyl compounds
(donors), iodine and iodine monochloride (acceptors). The negative value of
Gibb’s free energy of formation (∆G) also supports the formation of
thermodynamically stable complexes in the nine systems.
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REFERENCES
1. Kannappan, V. and Mahendran, S., National Symposium on Acoustics., 32, 2000.
2. Jaya Santhi, R., Ph.D. Thesis, University of Madras, 2002.
3. Prakash, S., Prasad, N., Singh, R. and Prakash, O., Acustica., 34, 1975, 121.
4. Szent-Gyorgyi, A., Introduction to a Sub-Molecular Biology., Academic Press, New
York, 1960.
5. Pfeiffer, P., Organische Molekullirbindungen., 2nd
Edn., Ferdinand Enke, Stuttgart,
1927.
6. Foster, R., Molecular Complexes, Vol.1, Science, London, 1973.
7. Tabhane, P., Ind. J. Pure and Appl. Phys., 20, 1977, 89.
8. Kannappan, V. and Kothai, S., J. Acous. Soc. Ind., 29, 2001, 169.
9. Kannappan, V. and Kothai, S., Ind. J. Pure and Appl. Phys., 40, 2002, 17.
10. Kannappan, V. and Kothai, S., J. Acous. Soc. Ind., 30, 2002, 76.
11. Kothai, S., Ph.D. Thesis, University of Madras, 2003.
12. De la mare, P.P.D., Electrophilic Halogenation, Chapter 10, Cambridge University
Press, London, 1976.
13. Material safety data sheet No. 12775, Baker Inc., 2006.
14. Amitha, N., Ph.D. Thesis, University of Madras, 1978.
15. Al Mokhtar Lambabhi, Widad Bouab, Muhamed Essaffar, Manual Alcami, Manual
Yanex and Jose-Luis, M, Abboud, New. J. Chem., 25, 2001, 509.
Page 171
TABLE 6.1
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ),
ABSORPTION COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU) AND RELAXATION
TIME (ττττ) AT VARIOUS CONCENTRATIONS OF IODINE MONOCHLORIDE - MESITYLENE SYSTEM
Solvent : n-hexane Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 ττττ /10-13
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 s
0.001 1061.5 638.7 3.37 1.39 11.6 6.0 6.2
0.002 1060.0 638.5 3.36 1.39 11.6 3.1 6.2
0.003 1065.2 642.1 3.40 1.37 11.5 13.0 6.2
0.004 1063.2 637.8 3.36 1.39 11.5 9.1 6.2
0.005 1059.2 640.3 3.39 1.39 11.7 1.5 6.3
0.006 1059.6 642.7 3.40 1.39 11.7 2.2 6.3
0.007 1060.2 636.2 3.36 1.40 11.7 3.3 6.3
0.008 1060.8 643.5 3.39 1.38 11.6 4.4 6.2
0.009 1063.8 639.8 3.39 1.38 11.6 10.0 6.2
0.010 1062.8 637.2 3.38 1.39 11.6 8.1 6.3
Plots : Fig. 6.1 U vs Concentration; Fig. 6.3 χU vs Concentration;
Fig. 6.2 κ vs Concentration;
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TABLE 6.2
FREE LENGTH (Lf), FREE VOLUME (Vf), INTERNAL PRESSURE (ππππi), COHESSIVE ENERGY (CE),
ACOUSTICAL IMPEDANCE (Z), AVAILABLE VOLUME (Va), LENARD JONES POTENTIAL (LJP),
AT VARIOUS CONCENTRATIONS OF IODINE MONOCHLORIDE - MESITYLENE SYSTEM
Solvent : n-hexane Temperature : 303 K
C Lf Vf /10-7 ππππi CE Z /105 Va /10-5 LJP
M Ao m3 atm kJ mol-1 kg-2 s-1 m3
0.001 0.7 5.0 2382 32.6 6.8 4.5 4.8
0.002 0.7 5.1 2379 32.5 6.8 4.6 4.8
0.003 0.7 5.0 2397 32.6 6.8 4.5 5.0
0.004 0.7 5.1 2373 32.5 6.8 4.5 4.9
0.005 0.7 5.0 2393 32.7 6.8 4.6 4.8
0.006 0.7 5.0 2402 32.7 6.8 4.5 4.8
0.007 0.7 5.1 2370 32.6 6.7 4.6 4.8
0.008 0.7 5.0 2400 32.6 6.8 4.5 4.8
0.009 0.7 5.0 2384 32.6 6.8 4.5 4.9
0.010 0.7 5.1 2376 32.6 6.8 4.5 4.9
Plots : Fig. 6.4 πi vs Concentration;
Fig. 6.5 CE vs Concentration;
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TABLE 6.3
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ),
ABSORPTION COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU) AND RELAXATION
TIME (ττττ) AT VARIOUS CONCENTRATIONS OF IODINE MONOCHLORIDE - PARA XYLENE SYSTEM
Solvent : n-hexane Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 ττττ /10-13
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 s
0.001 1062.2 641.2 3.34 1.38 11.4 7.3 6.1
0.002 1059.0 639.9 3.37 1.39 11.7 1.2 6.3
0.003 1065.8 645.0 3.41 1.36 11.5 14.1 6.2
0.004 1062.0 646.7 3.43 1.37 11.6 6.8 6.3
0.005 1061.2 638.2 3.37 1.39 11.6 5.3 6.2
0.006 1061.8 644.8 3.42 1.38 11.7 6.3 6.3
0.007 1059.2 642.1 3.40 1.39 11.7 1.4 6.3
0.008 1060.8 646.8 3.42 1.37 11.7 4.4 6.3
0.009 1060.6 643.4 3.41 1.38 11.7 3.9 6.3
0.010 1065.0 638.2 3.38 1.38 11.5 12.2 6.2
Plots : Fig. 6.1 U vs Concentration; Fig. 6.3 χU vs Concentration;
Fig. 6.2 κ vs Concentration;
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TABLE 6.4
FREE LENGTH (Lf), FREE VOLUME (Vf), INTERNAL PRESSURE (ππππi), COHESSIVE ENERGY (CE),
ACOUSTICAL IMPEDANCE (Z), AVAILABLE VOLUME (Va), LENARD JONES POTENTIAL (LJP),
AT VARIOUS CONCENTRATIONS OF IODINE MONOCHLORIDE - PARA XYLENE SYSTEM
Solvent : n-hexane Temperature : 303 K
C Lf Vf /10-7 ππππi CE Z /105 Va /10-5 LJP
M Ao m3 atm kJ mol-1 kg-2 s-1 m3
0.001 0.7 5.1 2375 32.3 6.8 4.5 4.9
0.002 0.7 5.0 2388 32.6 6.8 4.6 4.7
0.003 0.7 5.0 2406 32.6 6.9 4.5 5.0
0.004 0.7 4.9 2420 32.7 6.9 4.5 4.8
0.005 0.7 5.1 2378 32.6 6.8 4.6 4.8
0.006 0.7 4.9 2413 32.7 6.8 4.5 4.8
0.007 0.7 5.0 2403 32.7 6.8 4.5 4.8
0.008 0.7 4.9 2418 32.7 6.9 4.5 4.8
0.009 0.7 5.0 2406 32.7 6.8 4.5 4.8
0.010 0.7 5.1 2377 32.6 6.8 4.5 4.9
Plots : Fig. 6.4 πi vs Concentration;
Fig. 6.5 CE vs Concentration;
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TABLE 6.5
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ),
ABSORPTION COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU) AND RELAXATION
TIME (ττττ) AT VARIOUS CONCENTRATIONS OF IODINE MONOCHLORIDE - META XYLENE SYSTEM
Solvent : n-hexane Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 ττττ /10-13
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 s
0.001 1061.8 641.3 3.38 1.38 11.6 6.6 6.2
0.002 1062.4 638.8 3.37 1.39 11.6 7.7 6.2
0.003 1059.4 641.0 3.37 1.39 11.6 2.0 6.2
0.004 1060.8 643.2 3.39 1.38 11.6 4.6 6.3
0.005 1061.2 635.9 3.36 1.40 11.6 5.3 6.3
0.006 1065.2 640.4 3.37 1.38 11.5 12.8 6.2
0.007 1066.0 639.2 3.38 1.38 11.5 14.3 6.2
0.008 1062.8 643.0 3.39 1.38 11.5 8.2 6.2
0.009 1062.3 641.9 3.40 1.38 11.6 7.2 6.3
0.010 1062.4 636.3 3.35 1.39 11.5 7.4 6.2
Plots : Fig. 6.1 U vs Concentration; Fig. 6.3 χU vs Concentration;
Fig. 6.2 κ vs Concentration;
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TABLE 6.6
FREE LENGTH (Lf), FREE VOLUME (Vf), INTERNAL PRESSURE (ππππi), COHESSIVE ENERGY (CE),
ACOUSTICAL IMPEDANCE (Z), AVAILABLE VOLUME (Va), LENARD JONES POTENTIAL (LJP),
AT VARIOUS CONCENTRATIONS OF IODINE MONOCHLORIDE - META XYLENE SYSTEM
Solvent : n-hexane Temperature : 303 K
C Lf Vf /10-7 ππππi CE Z /105 Va /10-5 LJP
M Ao m3 atm kJ mol-1 kg-2 s-1 m3
0.001 0.7 5.0 2390 32.5 6.8 4.5 4.8
0.002 0.7 5.1 2382 32.6 6.8 4.5 4.9
0.003 0.7 5.0 2389 32.6 6.8 4.5 4.8
0.004 0.7 5.0 2401 32.6 6.8 4.5 4.8
0.005 0.7 5.1 2370 32.6 6.7 4.6 4.8
0.006 0.7 5.1 2381 32.5 6.8 4.5 5.0
0.007 0.7 5.1 2379 32.5 6.8 4.5 5.0
0.008 0.7 5.0 2394 32.5 6.8 4.5 4.9
0.009 0.7 5.0 2395 32.6 6.8 4.5 4.9
0.010 0.7 5.1 2363 32.5 6.8 4.6 4.9
Plots : Fig. 6.4 πi vs Concentration;
Fig. 6.5 CE vs Concentration;
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TABLE 6.7
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ),
ABSORPTION COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU) AND RELAXATION
TIME (ττττ) AT VARIOUS CONCENTRATIONS OF IODINE MONOCHLORIDE - ORTHO XYLENE SYSTEM
Solvent : n-hexane Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 ττττ /10-13
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 s
0.001 1069.2 639.0 3.38 1.37 11.4 20.7 6.2
0.002 1067.0 640.2 3.37 1.37 11.4 16.4 6.2
0.003 1061.4 640.8 3.40 1.39 11.7 5.7 6.3
0.004 1059.8 644.2 3.42 1.38 11.7 2.7 6.3
0.005 1065.2 637.4 3.38 1.38 11.5 12.9 6.2
0.006 1067.4 642.5 3.40 1.37 11.4 17.0 6.2
0.007 1062.5 639.7 3.42 1.38 11.7 7.6 6.3
0.008 1062.7 642.2 3.40 1.38 11.6 8.0 6.2
0.009 1061.2 643.1 3.40 1.38 11.6 5.1 6.3
0.010 1062.8 636.9 3.37 1.39 11.6 8.1 6.2
Plots : Fig. 6.1 U vs Concentration; Fig. 6.3 χU vs Concentration;
Fig. 6.2 κ vs Concentration;
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TABLE 6.8
FREE LENGTH (Lf), FREE VOLUME (Vf), INTERNAL PRESSURE (ππππi), COHESSIVE ENERGY (CE),
ACOUSTICAL IMPEDANCE (Z), AVAILABLE VOLUME (Va), LENARD JONES POTENTIAL (LJP),
AT VARIOUS CONCENTRATIONS OF IODINE MONOCHLORIDE - ORTHO XYLENE SYSTEM
Solvent : n-hexane Temperature : 303 K
C Lf Vf /10-7 ππππi CE Z /105 Va /10-5 LJP
M Ao m3 atm kJ mol-1 kg-2 s-1 m3
0.001 0.7 5.1 2378 32.5 6.8 4.5 5.1
0.002 0.7 5.1 2379 32.4 6.8 4.5 5.0
0.003 0.7 5.0 2398 32.7 6.8 4.5 4.8
0.004 0.7 4.9 2414 32.7 6.8 4.5 4.8
0.005 0.7 5.1 2378 32.6 6.8 4.5 5.0
0.006 0.7 5.0 2394 32.6 6.9 4.5 5.0
0.007 0.7 5.0 2397 32.7 6.8 4.5 4.9
0.008 0.7 5.0 2396 32.6 6.8 4.5 4.9
0.009 0.7 5.0 2400 32.6 6.8 4.5 4.8
0.010 0.7 5.1 2372 32.6 6.8 4.5 4.9
Plots : Fig. 6.4 πi vs Concentration;
Fig. 6.5 CE vs Concentration;
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TABLE 6.9
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ),
ABSORPTION COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU) AND RELAXATION
TIME (ττττ) AT VARIOUS CONCENTRATIONS OF IODINE MONOCHLORIDE - TOLUENE SYSTEM
Solvent : n-hexane Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 ττττ /10-13
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 s
0.001 1063.1 638.7 3.41 1.39 11.7 9.1 6.3
0.002 1061.4 638.6 3.39 1.39 11.7 5.8 6.3
0.003 1060.1 639.0 3.39 1.39 11.7 3.3 6.3
0.004 1059.8 638.7 3.40 1.39 11.8 2.7 6.3
0.005 1064.0 637.6 3.39 1.39 11.6 10.6 6.3
0.006 1063.0 639.5 3.39 1.38 11.6 8.7 6.3
0.007 1060.0 636.4 3.38 1.40 11.7 3.0 6.3
0.008 1060.4 639.9 3.38 1.39 11.7 3.7 6.3
0.009 1064.0 636.9 3.40 1.39 11.7 10.5 6.3
0.010 1060.0 635.9 3.37 1.40 11.7 2.8 6.3
Plots : Fig. 6.1 U vs Concentration; Fig. 6.3 χU vs Concentration;
Fig. 6.2 κ vs Concentration;
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TABLE 6.10
FREE LENGTH (Lf), FREE VOLUME (Vf), INTERNAL PRESSURE (ππππi), COHESSIVE ENERGY (CE),
ACOUSTICAL IMPEDANCE (Z), AVAILABLE VOLUME (Va), LENARD JONES POTENTIAL (LJP),
AT VARIOUS CONCENTRATIONS OF IODINE MONOCHLORIDE - TOLUENE SYSTEM
Solvent : n-hexane Temperature : 303 K
C Lf Vf /10-7 ππππi CE Z /105 Va /10-5 LJP
M Ao m3 atm kJ mol-1 kg-2 s-1 m3
0.001 0.7 5.0 2395 32.7 6.8 4.5 4.9
0.002 0.7 5.0 2387 32.6 6.8 4.5 4.8
0.003 0.7 5.0 2390 32.7 6.8 4.6 4.8
0.004 0.7 5.0 2394 32.7 6.8 4.6 4.8
0.005 0.7 5.0 2383 32.7 6.8 4.5 4.9
0.006 0.7 5.0 2389 32.6 6.8 4.5 4.9
0.007 0.7 5.0 2378 32.6 6.7 4.6 4.8
0.008 0.7 5.0 2389 32.6 6.8 4.5 4.8
0.009 0.7 5.0 2383 32.7 6.8 4.5 4.9
0.010 0.7 5.1 2373 32.6 6.7 4.6 4.8
Plots : Fig. 6.4 πi vs Concentration;
Fig. 6.5 CE vs Concentration;
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TABLE 6.11
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ),
ABSORPTION COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU) AND RELAXATION
TIME (ττττ) AT VARIOUS CONCENTRATIONS OF IODINE MONOCHLORIDE - BENZENE SYSTEM
Solvent : n-hexane Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 ττττ /10-13
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 s
0.001 1067.2 637.2 3.39 1.38 11.5 16.9 6.2
0.002 1062.4 637.0 3.39 1.39 11.7 7.7 6.3
0.003 1062.0 637.9 3.42 1.39 11.8 6.9 6.3
0.004 1060.0 636.0 3.39 1.40 11.8 3.1 6.3
0.005 1064.0 637.6 3.38 1.39 11.6 10.6 6.2
0.006 1062.5 638.6 3.41 1.39 11.7 7.7 6.3
0.007 1060.8 636.7 3.37 1.40 11.7 4.5 6.3
0.008 1059.8 640.4 3.40 1.39 11.7 2.5 6.3
0.009 1058.7 636.1 3.39 1.40 11.8 0.4 6.3
0.010 1057.6 635.0 3.34 1.41 11.7 -1.7 6.3
Plots : Fig. 6.1 U vs Concentration; Fig. 6.3 χU vs Concentration;
Fig. 6.2 κ vs Concentration;
Page 182
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TABLE 6.12
FREE LENGTH (Lf), FREE VOLUME (Vf), INTERNAL PRESSURE (ππππi), COHESSIVE ENERGY (CE),
ACOUSTICAL IMPEDANCE (Z), AVAILABLE VOLUME (Va), LENARD JONES POTENTIAL (LJP),
AT VARIOUS CONCENTRATIONS OF IODINE MONOCHLORIDE - BENZENE SYSTEM
Solvent : n-hexane Temperature : 303 K
C Lf Vf /10-7 ππππi CE Z /105 Va /10-5 LJP
M Ao m3 atm kJ mol-1 kg-2 s-1 m3
0.001 0.7 5.1 2377 32.6 6.8 4.5 5.0
0.002 0.7 5.0 2384 32.7 6.8 4.5 4.9
0.003 0.7 4.9 2398 32.8 6.8 4.5 4.8
0.004 0.7 5.0 2382 32.7 6.7 4.6 4.8
0.005 0.7 5.1 2378 32.6 6.8 4.5 4.9
0.006 0.7 5.0 2393 32.7 6.8 4.5 4.9
0.007 0.7 5.0 2378 32.6 6.8 4.6 4.8
0.008 0.7 5.0 2397 32.7 6.8 4.5 4.8
0.009 0.7 5.0 2382 32.7 6.7 4.6 4.7
0.010 0.7 5.1 2364 32.5 6.7 4.6 4.7
Plots : Fig. 6.4 πi vs Concentration;
Fig. 6.5 CE vs Concentration;
Page 183
183
TABLE 6.13
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ),
ABSORPTION COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU) AND RELAXATION
TIME (ττττ) AT VARIOUS CONCENTRATIONS OF IODINE MONOCHLORIDE - ANTHRACENE SYSTEM
Solvent : n-hexane Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 ττττ /10-13
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 s
0.001 1066.0 638.2 3.37 1.38 11.5 14.3 6.2
0.002 1061.6 637.2 3.39 1.39 11.7 5.7 6.3
0.003 1059.2 636.9 3.36 1.40 11.7 0.9 6.3
0.004 1058.8 638.9 3.39 1.40 11.8 -0.1 6.3
0.005 1058.4 637.1 3.37 1.40 11.7 -1.2 6.3
0.006 1059.6 639.4 3.37 1.39 11.7 0.8 6.3
0.007 1058.8 638.8 3.37 1.40 11.7 -1.0 6.3
0.008 1064.4 640.8 3.39 1.38 11.5 9.4 6.2
0.009 1064.0 643.2 3.42 1.37 11.6 8.3 6.3
0.010 1062.8 636.8 3.39 1.39 11.7 5.8 6.3
Plots : Fig. 6.6 U vs Concentration; Fig. 6.8 χU vs Concentration;
Fig. 6.7 κ vs Concentration;
Page 184
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TABLE 6.14
FREE LENGTH (Lf), FREE VOLUME (Vf), INTERNAL PRESSURE (ππππi), COHESSIVE ENERGY (CE),
ACOUSTICAL IMPEDANCE (Z), AVAILABLE VOLUME (Va), LENARD JONES POTENTIAL (LJP),
AT VARIOUS CONCENTRATIONS OF IODINE MONOCHLORIDE - ANTHRACENE SYSTEM
Solvent : n-hexane Temperature : 303 K
C Lf Vf /10-7 ππππi CE Z /105 Va /10-5 LJP
M Ao m3 atm kJ mol-1 kg-2 s-1 m3
0.001 0.7 5.1 2376 32.5 6.8 4.5 5.0
0.002 0.7 5.0 2384 32.7 6.8 4.6 4.8
0.003 0.7 5.1 2376 32.6 6.7 4.6 4.8
0.004 0.7 5.0 2391 32.7 6.8 4.6 4.7
0.005 0.7 5.0 2378 32.6 6.7 4.6 4.7
0.006 0.7 5.0 2383 32.6 6.8 4.6 4.8
0.007 0.7 5.0 2382 32.6 6.8 4.6 4.7
0.008 0.7 5.0 2384 32.6 6.8 4.5 4.9
0.009 0.7 5.0 2401 32.7 6.8 4.5 4.9
0.010 0.7 5.0 2377 32.7 6.8 4.6 4.9
Plots : Fig. 6.9 πi vs Concentration;
Fig. 6.10 CE vs Concentration;
Page 185
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TABLE 6.15
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ),
ABSORPTION COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU) AND RELAXATION
TIME (ττττ) AT VARIOUS CONCENTRATIONS OF IODINE MONOCHLORIDE - BIPHENYL SYSTEM
Solvent : n-hexane Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 ττττ /10-13
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 s
0.001 1061.3 638.9 3.36 1.39 11.6 5.6 6.2
0.002 1059.2 637.4 3.38 1.40 11.7 1.5 6.3
0.003 1057.7 638.4 3.37 1.40 11.7 -1.4 6.3
0.004 1060.8 636.7 3.36 1.40 11.6 4.3 6.2
0.005 1062.4 636.8 3.34 1.39 11.5 7.3 6.2
0.006 1058.4 639.5 3.36 1.40 11.7 -0.4 6.3
0.007 1060.8 638.6 3.38 1.39 11.7 4.0 6.3
0.008 1065.2 643.3 3.39 1.37 11.5 12.3 6.2
0.009 1066.6 638.0 3.35 1.38 11.4 14.8 6.2
0.010 1063.2 637.2 3.36 1.39 11.5 8.3 6.2
Plots : Fig. 6.6 U vs Concentration; Fig. 6.8 χU vs Concentration;
Fig. 6.7 κ vs Concentration;
Page 186
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TABLE 6.16
FREE LENGTH (Lf), FREE VOLUME (Vf), INTERNAL PRESSURE (ππππi), COHESSIVE ENERGY (CE),
ACOUSTICAL IMPEDANCE (Z), AVAILABLE VOLUME (Va), LENARD JONES POTENTIAL (LJP),
AT VARIOUS CONCENTRATIONS OF IODINE MONOCHLORIDE - BIPHENYL SYSTEM
Solvent : n-hexane Temperature : 303 K
C Lf Vf /10-7 ππππi CE Z /105 Va /10-5 LJP
M Ao m3 atm kJ mol-1 kg-2 s-1 m3
0.001 0.7 5.1 2378 32.5 6.8 4.5 4.8
0.002 0.7 5.0 2384 32.7 6.8 4.6 4.8
0.003 0.7 5.0 2383 32.6 6.8 4.6 4.7
0.004 0.7 5.1 2371 32.5 6.8 4.6 4.8
0.005 0.7 5.1 2365 32.5 6.8 4.6 4.9
0.006 0.7 5.1 2382 32.6 6.8 4.6 4.7
0.007 0.7 5.0 2381 32.6 6.8 4.6 4.8
0.008 0.7 5.0 2393 32.5 6.9 4.5 5.0
0.009 0.7 5.1 2363 32.4 6.8 4.5 5.0
0.010 0.7 5.1 2367 32.5 6.8 4.5 4.9
Plots : Fig. 6.9 πi vs Concentration;
Fig. 6.10 CE vs Concentration;
Page 187
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TABLE 6.17
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ),
ABSORPTION COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU) AND RELAXATION
TIME (ττττ) AT VARIOUS CONCENTRATIONS OF IODINE MONOCHLORIDE - NAPHTHALENE SYSTEM
Solvent : n-hexane Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 ττττ /10-13
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 s
0.001 1063.5 637.3 3.35 1.39 11.5 9.7 6.2
0.002 1059.7 636.4 3.31 1.40 11.5 2.3 6.2
0.003 1057.7 636.6 3.35 1.40 11.7 -1.6 6.3
0.004 1056.7 635.0 3.35 1.41 11.7 -3.7 6.3
0.005 1053.6 635.0 3.35 1.42 11.8 -9.7 6.3
0.006 1052.7 634.1 3.34 1.42 11.9 -11.5 6.3
0.007 1052.6 633.1 3.33 1.43 11.8 -11.9 6.3
0.008 1063.2 634.9 3.32 1.39 11.4 8.0 6.2
0.009 1061.2 637.5 3.35 1.39 11.6 4.0 6.2
0.010 1058.8 638.1 3.38 1.40 11.7 -0.7 6.3
Plots : Fig. 6.6 U vs Concentration; Fig. 6.8 χU vs Concentration;
Fig. 6.7 κ vs Concentration;
Page 188
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TABLE 6.18
FREE LENGTH (Lf), FREE VOLUME (Vf), INTERNAL PRESSURE (ππππi), COHESSIVE ENERGY (CE),
ACOUSTICAL IMPEDANCE (Z), AVAILABLE VOLUME (Va), LENARD JONES POTENTIAL (LJP),
AT VARIOUS CONCENTRATIONS OF IODINE MONOCHLORIDE - NAPHTHALENE SYSTEM
Solvent : n-hexane Temperature : 303 K
C Lf Vf /10-7 ππππi CE Z /105 Va /10-5 LJP
M Ao m3 atm kJ mol-1 kg-2 s-1 m3
0.001 0.7 5.1 2371 32.5 6.8 4.5 4.9
0.002 0.7 5.2 2357 32.3 6.7 4.6 4.8
0.003 0.7 5.1 2374 32.6 6.7 4.6 4.7
0.004 0.7 5.1 2368 32.6 6.7 4.6 4.7
0.005 0.7 5.1 2371 32.6 6.7 4.6 4.6
0.006 0.7 5.1 2367 32.6 6.7 4.7 4.5
0.007 0.7 5.1 2359 32.6 6.7 4.7 4.5
0.008 0.7 5.2 2350 32.4 6.8 4.6 4.9
0.009 0.7 5.1 2369 32.5 6.8 4.6 4.8
0.010 0.7 5.0 2382 32.6 6.8 4.6 4.7
Plots : Fig. 6.9 πi vs Concentration;
Fig. 6.10 CE vs Concentration;
Page 189
189
TABLE 6.19
MEAN VALUES OF GIBB'S FREE ENERGY OF FORMATION (∆G), MEAN VALUES OF
GIBB'S FREE ENERGY OF ACTIVATION (∆G#) AND MEAN VALUES FORMATION CONSTANT (K)
OF HYDROCARBON COMPOUNDS WITH IODINE MONOCHLORIDE IN n-HEXANE SOLUTIONS
Solvent : n-hexane Temperature : 303 K
∆G ∆G# K
DONOR kJ mol-1 kJ mol-1 dm-3 mol-1
mesitylene -9.9 3.8 50.4
p-xylene -9.7 3.8 46.9
m-xylene -9.6 3.8 45.1
o-xylene -9.4 3.8 41.4
toluene -9.0 3.8 35.1
benzene -8.7 3.8 32.2
anthracene -11.3 3.8 90.5
biphenyl -10.8 3.8 74.1
naphthalene -10.0 3.8 52.5
Page 190
Fig. 6.1 Plots of Ultrasonic velocity vs Concentration
1056
1058
1060
1062
1064
1066
1068
1070
0.000 0.002 0.004 0.006 0.008 0.010 0.012
Concentration, M
U,
m s
-1
IC-MST IC-PXL IC-MXLIC-OXL IC-BZ IC-TL
Solvent : n-hexane Temperature : 303 K
Fig. 6.2 Plots of Adiabatic compressibility vs Concentration
1.36
1.37
1.38
1.39
1.40
1.41
1.42
0.000 0.002 0.004 0.006 0.008 0.010 0.012
Concentration, M
κκ κκ /
10
-9,
kg
-1m
s2
IC-MST IC-PXLIC-MXL IC-OXLIC-BZ IC-TL
Solvent : n-hexane Temperature : 303 K
Page 191
191
Fig. 6.3 Plots of Molecular interaction parameter vs Concentration
-5
0
5
10
15
20
25
0.000 0.002 0.004 0.006 0.008 0.010 0.012
Concentration, M
χχ χχU/1
0-3
, m
s-1
IC-MST IC-PXL
IC-MXL IC-OXL
IC-BZ IC-TL
Solvent : n-hexane Temperature : 303 K
Fig. 6.4 Plots of Internal pressure vs Concentration
2360
2380
2400
2420
2440
0.000 0.002 0.004 0.006 0.008 0.010 0.012
Concentration, M
ππ ππi, a
tm
IC-MST IC-PXL IC-MXL
IC-OXL IC-BZ IC-TL
Solvent : n-hexane Temperature : 303 K
Page 192
192
Fig. 6.5 Plots of Cohessive energy vs Concentration
32.3
32.4
32.5
32.6
32.7
32.8
32.9
0.000 0.002 0.004 0.006 0.008 0.010 0.012
Concentration, M
CE
, kJ m
ol-1
IC-MST IC-PXL
IC-MXL IC-OXL
IC-BZ IC-TL
Fig. 6.6 Plots of Ultrasonic velocity vs Concentration
1048
1052
1056
1060
1064
1068
0.000 0.002 0.004 0.006 0.008 0.010 0.012
Concentration, M
U,
ms
-1
IC-ANTIC-BIPIC-NAP
Solvent : n-hexane Temperature : 303 K
Page 193
193
Fig. 6.7 Plots of Adiabatic compressibility vs Concentration
1.36
1.38
1.40
1.42
1.44
0.000 0.002 0.004 0.006 0.008 0.010 0.012
Concentration, M
κκ κκ /
10
-9,
kg
-1 m
s2
IC-ANTIC-BIPIC-NAP
Fig. 6.8 Plots of Molecular interaction parameter vs Concentration
-16
-11
-6
-1
4
9
14
0.000 0.002 0.004 0.006 0.008 0.010 0.012
Concentration, M
χχ χχU/1
0-3
, m
s-1
IC-ANTIC-BIPIC-NAP
Page 194
194
Fig. 6.9 Plots of Internal pressure vs Concentration
2340
2365
2390
0.000 0.002 0.004 0.006 0.008 0.010 0.012
Concentration, M
ππ ππi, a
tm
IC-ANTIC-BIPIC-NAP
Solvent : n-hexane Temperature : 303 K
Fig. 6.10 Plots of Cohesive energy vs Concentration
32.3
32.4
32.5
32.6
32.7
32.8
0.000 0.002 0.004 0.006 0.008 0.010 0.012
Concentration, M
CE
, kJ m
ol-1
IC-ANTIC-BIPIC-NAP
Page 196
196
CHAPTER – 7
ULTRASONIC STUDIES ON THE CHARGE TRANSFER
COMPLEXES OF IODINE AND CERTAIN PHENOLS AT 303 K
7.1. INTRODUCTION
Phenols are important class of aromatic compounds and they are
widely used in the manufacturer of several dyes and drugs1. They undergo
electrophilic substitution reactions2-4 with several electrophiles. In these
reactions, it is suggested that the first step is the formation of a loose
complex between phenol and the electrophile. It may be pointed out that
phenol undergoes electrophilic substitution more easily than benzene. Thus,
phenolic group activates the benzene ring in electrophilic substitution
reaction. Phenols may form complexes with electron deficient species.
Venkateswarlu and coworkers investigated the donor abilities of phenols
and their tendency to form change transfer complexes with
π acceptors5. They also studied the charge transfer spectra, stability and
thermodynamic parameters of charge transfer complexes of phenols with
2,3-dichloro-5,6-dicyano-p-benzoquinone6 (DDQ). Literature Survey reveals
that DDQ forms charge transfer complexes with phenols and produces a
characteristic colour in methanol7,8, but the colour fades with time
indicating that these complexes are unstable and soon turn into other
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197
products. It has been reported that charge transfer complexes can be
stabilized for a longer time in solvents of low polarity at low temperatures
and under low donor concentration9,10.
Iodine is an important halogen which functions as acceptor. It forms
complexes with several π as well as n electron donors. Complexes of iodine
with carbon tetrachloride and olefins are well known11. Optical methods
have been used to determine the formation constant of these complexes. A
mixture of iodine and phenols at low concentration is used as antiseptic and
disinfectant. Iodine can form change transfer complexes with phenols. In
this chapter, ultrasonic studies have been carried out to determine the
formation constants of iodine and phenols at 303 K. Ultrasonic velocity,
density and viscosities are measured for systems containing equimolar
concentrations of donor (phenol) and acceptor (iodine) in solution. Wide
concentration range of 1x10-3 – 20x10-3 M has been chosen to study the
influence of concentration on the complexation. The donors used in the
present study are phenol, o-cresol, p-cresol, m-cresol and carvacrol. Less
polar liquids like n-hexane, carbon tetrachloride, chloroform and
dichloromethane are used as solvents in the present investigation. In order
to establish the formation of CT complexes in these systems, acoustical
parameters like adiabatic compressibility, free length, molecular interaction
parameter, internal pressure and cohesive energy are also computed and
reported.
Page 198
198
7.2 Results and Discussion
The measured ultrasonic velocity (U) for iodine - phenol systems in
dichloromethane along with density and viscosity values are presented in
Table 7.1 – 7.5. Plots of ultrasonic velocity vs concentration are given Fig
7.1. It is found that the ultrasonic velocity in general decreases with
increase in concentration, and density increases with concentration.
However, there is no significant change in viscosity. This observation shows
that iodine forms a charge transfer complex with phenols. The ultrasonic
velocity, density and viscosity values for the five systems in chloroform are
in Tables 7.6 – 7.10, while the values in carbon tetrachloride are given in
Figs. 7.11 - 7.15. Tables 7.16 – 7.20 contain the measured values ultrasonic
velocity, density and viscosity for iodine-phenol systems in n-hexane at 303
K. It may be noted that in each solvent, the ultrasonic velocity is minimum
at a characteristic concentration the complexation may be maximum at this
concentration. This is as supported by the higher density value at this
concentration.
Adiabatic compressibility (κ) values are calculated for different
iodine-phenol systems in four solvents at various concentrations and they
are given in Tables 7.1 – 7.20. Plots of adiabatic compressibility vs
concentration for the twenty systems are given in Figs. 7.2, 7.7, 7.12 and
7.17. It is seen from the data in the Tables and Plots in the figures that
Page 199
199
adiabatic compressibility values decrease with concentration and it is
minimum at a characteristic concentration for each system. Thus, extent of
complex formation is concentration dependent and there is a specific
concentration for each system at which complexation is maximum. Thus,
the trend in adiabatic compressibility values also establishes the formation
of charge transfer complexes between phenols and iodine in the four
solvents.
Free length (Lf) values are computed for all the systems and presented
in Tables 7.1 – 7.20. It is found that the free length values in the mixtures
containing donor and acceptor are slightly greater than those of pure
components (Table 7.22). This may be due to the association of phenols and
iodine. Further, the free length values are found to be almost constant in all
the systems suggesting the formation of similar complexes in these systems.
Attenuation constant (α/f2) values are calculated from the measured
ultrasonic velocity, density and viscosity for all the systems. Generally, the
absorption coefficient value increases slightly with increase in concentration
may be due to increase in the extent of complexation with increase in
concentration.
Molecular interaction parameter (χU) with respect to velocity in a
liquid mixture is indicative of the extent of deviation from ideal behaviour.
Page 200
200
This indication may be due to the formation of a charge transfer complex
between the components of the mixture. Molecular interaction parameter
values are calculated from the observed ultrasonic velocity values and ideal
mixing values of the mixtures containing the donor and the acceptor. These
values are given in Tables 7.1 - 7.20. Figures 7.3, 7.8, 7.13 and 7.18
contain the plots of molecular interaction parameter vs concentration for the
twenty systems. It is found that molecular interaction parameter values are
either positive or negative depending upon the system and concentration.
Thus, charge transfer complexes are formed between iodine and phenols.
Further, decrease in molecular interaction parameter values at higher
concentration suggests that the degree of complexation increases with
increase in concentration. Large negative values of molecular interaction
parameter are observed at a specific concentration for each system. Hence,
maximum complexation is expected at characteristic concentration for each
system.
Internal pressure (πi) in a liquid system is indicative of the
intermolecular attractive forces between the component molecules. In binary
and ternary liquid mixtures internal pressure value is a measure of
attractive forces between components. Internal pressure values are
calculated for all the systems (Table 7.1 – 7.20). Plots of internal pressure vs
concentration are given in Figs. 7.4, 7.9, 7.14, and 7.19 for all the twenty
systems investigated. It is found that internal pressure values in the
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201
solution containing donor and acceptor are different from the internal
pressure values of the component liquids (Table 7.22). There are attractive
forces between iodine and phenol molecules in the ternary mixtures as the
internal pressure values are also different from the internal pressure values
of the solvents. This may be due to the formation of charge transfer
complexes between iodine and phenol. Increase in internal pressure values
in a given system with increase in concentration suggests that the extent of
complexation increases with concentration. It may be noted that in a given
system, internal pressure value is higher at a specific concentration. Thus,
the extent of complexation is maximum at a particular concentration which
is characteristic of the system.
Cohesive energy (CE) in a liquid mixture is also a measure of
intermolecular molecular forces between the component molecules.
Cohesive energy values are computed for all the twenty systems and they
are listed in Tables 7.1 – 7.20. Plots of cohesive energy against
concentration are presented in Figs. 7.5, 7.10, 7.15 and 7.20. It is evident
from the data in the Tables and the plots in the Figures that the cohesive
energy values are close to the cohesive energy values of pure solvents (Table
7.22). This is justified because the solvent is the major component in all the
systems. However, the cohesive energy values differ slightly from the
cohesive energy values of pure solvents indicating the presence of
intermolecular attractive forces. Cohesive energy generally decreases with
Page 202
202
increase in concentration and it is minimum for a given system at a
particular concentration. This observation also suggests that the extent of
complexation is maximum at characteristic concentration.
The main aim of the present work is to evaluate the formation
constants (K) of charge transfer complexes formed between iodine (acceptor)
and five structurally different phenols (donors) in four different solvents. The
effect of substituent in phenol and the influence of polarity of the medium
can be investigated by calculating formation constant values for the twenty
systems. Bhatt et al have suggested a method to compute stability constant
values for the complexes formed in binary mixtures from the measured
ultrasonic velocity12. However, this method has the limitation that it can be
applied to charge transfer complexes which are relatively stable and in
solutions of moderate concentration13. Recently, Kannappan and coworkers
have derived an equation to calculate the formation constants of even weak
complexes14,15. This equation has been successfully applied to several
ternary mixtures to calculate the formation constants of complexes16,17. In
the present work, the equation suggested by Kannappan is used to calculate
the formation constant of charge transfer complexes formed between iodine
and phenols in four different solvents. Less polar solvents with low dielectric
constants are used in the present work so that the charge transfer
complexes are not destabilised by the solvents due to solvation.
Page 203
203
The mean stability constant values for all the twenty charge transfer
complexes are shown in table 7.21. The stability of the complexes depends
upon the structure of the phenol and the order of stability according to the
structure of donor is
o-cresol > p-cresol > m–cresol > phenol > carvacrol
The effect of substituents on the stability of the iodine-phenol charge
transfer complex is attributed to the interaction of substituents with the π-
orbitals of the benzene ring of phenol. The hyperconjucative and inductive
effect of methyl group and isopropyl group perturb the resonance in benzene
ring and boost the energy level of the donor and bring it closer to the LUMO
of iodine and this enhances the stability of the complex. Since the inductive
effect and hyper conjugative effect are possible in ortho and para isomers of
cresols, these two phenols form more stable complexes with phenol. In the
case of m-cresol, only inductive effect is possible and hence, the charge
transfer complex of iodine and m-cresol is slightly less stable than those of
ortho and para isomers. In the case of carvacrol, the presence of both
methyl and isopropyl groups in the benzene ring may contribute to the
stability but the presence of bulky isopropyl group and methyl substituted
higher approach of acceptor (iodine) molecule and this steric effect
predominates over the milder inductive effect. This is indicated by the
smaller stability constant value of iodine-carvacrol complex than those of
iodine and other phenols used as donors in the present work.
Page 204
204
The formation of charge transfer complex between iodine and phenol
involves the polarization of π-electronic cloud by the acceptor. Thus, there is
induced dipole created in the charge transfer complex besides the
permanent dipole present in phenol. In order to establish this, the solvent
effect on the stability of the charge transfer complexes is investigated. The
formation constants are evaluated in four less polar solvents. These solvents
differ in the dielectric constant only slightly. The extent of solvation may be
greater for a given complex in a solvent of higher dielectric constant. It is
found that for a given charge transfer complex, the formation constants are
slightly greater in the slightly polar solvents like chloroform and
dichloromethane and less in non-polar solvents like n–hexane and carbon
tetrachloride.
The free energy of formation (∆G) values are computed from the mean
values of stability constant and they are presented in Table 7.21 along with
the relaxation time (τ). The free energy of formation is negative for all the
complexes indicating the formation of stable complexes between iodine and
all the phenols. Relaxation time values are found to be constant and
independent of concentration for a given system. Since free energy of
formation and relaxation time values are intrinsic properties of a complex,
these values do not depend upon the concentration. It may be noted that,
the relaxation time differs slightly from those of donor systems and also
relaxation time values of pure solvents.
Page 205
205
REFERENCES
1. Francis A Carey, Organic Chemistry, 5th
Edn., Tata McGraw Hill Publishing
Comapany Ltd., New Delhi, 2005.
2. March, J., Advanced Organic Chemistry, 4th
Edn., John Wiley, New York, 1992.
3. Robert Thornton Morrison and Robert Neilson Boyd, Organic Chemistry, 6th
Edn.,
Prientice Hall of India Pvt. Ltd., New Delhi, 2006.
4. Pine Stanely, H., Hendrickson, B., Cran, D.J. and Hammond, G.S., Organic
Chemistry, McGraw Hill, GB, 1989.
5. Shanta, M., Suresh, T. and Venkateshwarlu, G., Ind. J. Chem., 37(A), 1998, 1119.
6. Vinodkumar, T, Veeraiah, T. and Venkateshwarlu, G., Proc. Indian Acad. Sci.
(Chem. Sci.), 112, 2000, 119.
7. Becker, H.D., J. Org. Chem., 30, 1965, 982.
8. Hewgill, F.R. and Howie, G. B., Aust. J. Chem., 31, 1978, 907.
9. Rappoport, Z., J. Chem. Soc., 1963, 4498.
10. Rappoport, Z. and Harowitz, A., J. Chem. Soc., 1964, 1348.
11. De la mare, P.P.D., Electrophilic Halogenation, Chapter 10, Cambridge University
Press, London, 1976.
12. Marwein, B.L. and Bhatt, S.N., Thermochimica Acta, 118, 1987, 277.
13. Marwein, B.L. and Bhatt, S.N., Acustica, 58, 1985, 243.
14. Kannappan, V. and Kothai, S., J. Acous. Soc. Ind., 29(1), 2001, 169.
15. Kannappan, V. and Jaya Santhi, R., Ind. J. Pure & Appl. Phys., 43,
2005, 167.
16. Kannappan, V. and Kothai, S., Ind. J. Pure & Appl. Phys., 40, 2002, 17.
17. Indra Gandhi, N., Ph.D. Thesis, University of Madras, 2006.
Page 206
TABLE 7.1
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE) AND ACOUSTIC IMPEDANCE (Z) AT VARIOUS CONCENTRATIONS
OF IODINE - ORTHO CRESOL SYSTEM
Solvent : dichloromethane Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 1058.2 1136.3 5.08 0.79 9.9 9.4 0.6 4375 33.1 12.0
0.002 1055.2 1136.2 5.08 0.79 10.0 3.6 0.6 4382 33.2 12.0
0.004 1052.8 1136.8 5.10 0.79 10.1 -1.2 0.6 4393 33.3 12.0
0.006 1050.0 1138.2 5.09 0.80 10.2 -6.7 0.6 4398 33.3 12.0
0.010 1051.4 1138.7 5.05 0.79 10.0 -4.4 0.6 4377 33.1 12.0
0.015 1048.8 1139.6 5.08 0.80 10.2 -9.9 0.6 4392 33.2 12.0
0.020 1047.6 1139.9 5.10 0.80 10.2 -12.6 0.6 4403 33.3 11.9
Plots : Fig. 7.1 U vs Concentration; Fig. 7.3 χU vs Concentration; Fig. 7.5 CE vs Concentration;
Fig. 7.2 κ vs Concentration; Fig. 7.4 πi vs Concentration;
Page 207
207
TABLE 7.2
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE) AND ACOUSTIC IMPEDANCE (Z) AT VARIOUS CONCENTRATIONS
OF IODINE - PARA CRESOL SYSTEM
Solvent : dichloromethane Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 1040.0 1137.7 5.03 0.81 10.3 -25.0 0.6 4396 33.2 11.8
0.002 1043.6 1138.1 5.05 0.81 10.3 -18.3 0.6 4397 33.2 11.9
0.004 1048.0 1137.4 5.07 0.80 10.2 -10.1 0.6 4393 33.3 11.9
0.006 1047.6 1139.2 5.09 0.80 10.2 -11.1 0.6 4403 33.3 11.9
0.010 1046.0 1139.5 5.11 0.80 10.3 -14.4 0.6 4414 33.4 11.9
0.015 1040.0 1140.0 5.07 0.81 10.4 -26.0 0.6 4408 33.3 11.9
0.020 1050.6 1140.6 5.06 0.79 10.1 -6.4 0.6 4380 33.1 12.0
Plots : Fig. 7.1 U vs Concentration; Fig. 7.3 χU vs Concentration; Fig. 7.5 CE vs Concentration;
Fig. 7.2 κ vs Concentration; Fig. 7.4 πi vs Concentration;
Page 208
208
TABLE 7.3
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE) AND ACOUSTIC IMPEDANCE (Z) AT VARIOUS CONCENTRATIONS
OF IODINE - META CRESOL SYSTEM
Solvent : dichloromethane Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 1047.8 1135.3 5.06 0.80 10.2 -10.3 0.6 4384 33.2 11.9
0.002 1049.2 1136.7 5.03 0.80 10.1 -7.8 0.6 4373 33.1 11.9
0.004 1050.0 1137.9 5.02 0.80 10.0 -6.5 0.6 4367 33.0 11.9
0.006 1051.6 1138.3 5.01 0.79 10.0 -3.6 0.6 4360 33.0 12.0
0.010 1054.8 1138.5 4.99 0.79 9.8 2.1 0.6 4342 32.9 12.0
0.015 1055.9 1138.7 4.99 0.79 9.8 3.7 0.6 4339 32.9 12.0
0.020 1047.2 1139.9 4.98 0.80 10.0 -13.3 0.6 4350 32.9 11.9
Plots : Fig. 7.1 U vs Concentration; Fig. 7.3 χU vs Concentration; Fig. 7.5 CE vs Concentration;
Fig. 7.2 κ vs Concentration; Fig. 7.4 πi vs Concentration;
Page 209
209
TABLE 7.4
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE) AND ACOUSTIC IMPEDANCE (Z) AT VARIOUS CONCENTRATIONS
OF IODINE - PHENOL SYSTEM
Solvent : dichloromethane Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 1054.4 1135.7 5.11 0.79 10.1 2.2 0.6 4393 33.3 12.0
0.002 1050.0 1136.9 5.09 0.80 10.2 -6.3 0.6 4396 33.3 11.9
0.004 1048.8 1137.8 5.05 0.80 10.1 -8.7 0.6 4385 33.2 11.9
0.006 1055.6 1136.7 5.06 0.79 9.9 4.0 0.6 4369 33.1 12.0
0.010 1055.2 1138.7 5.04 0.79 9.9 2.8 0.6 4362 33.0 12.0
0.015 1053.6 1139.0 5.03 0.79 9.9 -0.7 0.6 4360 33.0 12.0
0.020 1050.8 1139.5 5.04 0.79 10.0 -6.5 0.6 4367 33.1 12.0
Plots : Fig. 7.1 U vs Concentration; Fig. 7.3 χU vs Concentration; Fig. 7.5 CE vs Concentration;
Fig. 7.2 κ vs Concentration; Fig. 7.4 πi vs Concentration;
Page 210
210
TABLE 7.5
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE) AND ACOUSTIC IMPEDANCE (Z) AT VARIOUS CONCENTRATIONS
OF IODINE - CARVACROL SYSTEM
Solvent : dichloromethane Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 1048.0 1134.9 5.00 0.80 10.1 -9.9 0.6 4359 33.1 11.9
0.002 1056.4 1136.2 4.97 0.79 9.8 5.9 0.6 4330 32.8 12.0
0.004 1046.8 1137.2 5.00 0.80 10.1 -12.5 0.6 4364 33.0 11.9
0.006 1049.2 1138.1 5.00 0.80 10.0 -8.1 0.6 4358 33.0 11.9
0.010 1050.0 1137.9 5.01 0.80 10.0 -7.0 0.6 4355 33.0 11.9
0.015 1043.2 1139.9 5.01 0.81 10.2 -20.3 0.6 4374 33.1 11.9
0.020 1050.0 1139.2 5.00 0.80 10.0 -7.9 0.6 4347 32.9 12.0
Plots : Fig. 7.1 U vs Concentration; Fig. 7.3 χU vs Concentration; Fig. 7.5 CE vs Concentration;
Fig. 7.2 κ vs Concentration; Fig. 7.4 πi vs Concentration;
Page 211
211
TABLE 7.6
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE) AND ACOUSTIC IMPEDANCE (Z) AT VARIOUS CONCENTRATIONS
OF IODINE - ORTHO CRESOL SYSTEM
Solvent : chloroform
Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 956.2 1276.4 6.05 0.86 14.3 -20.8 0.6 3650 34.6 12.2
0.002 955.2 1277.7 6.03 0.86 14.2 -23.0 0.6 3647 34.5 12.2
0.004 950.0 1277.0 6.03 0.87 14.5 -33.9 0.6 3655 34.6 12.1
0.006 962.5 1279.0 5.98 0.84 13.8 -8.7 0.6 3619 34.2 12.3
0.010 961.6 1279.3 6.00 0.85 13.9 -11.2 0.6 3626 34.3 12.3
0.015 966.4 1281.2 6.03 0.84 13.7 -2.1 0.6 3628 34.3 12.4
0.020 969.4 1281.6 6.00 0.83 13.5 3.2 0.6 3613 34.1 12.4
Plots : Fig. 7.6 U vs Concentration; Fig. 7.8 χU vs Concentration; Fig. 7.10 CE vs Concentration;
Fig. 7.7 κ vs Concentration; Fig. 7.9 πi vs Concentration;
Page 212
212
TABLE 7.7
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE) AND ACOUSTIC IMPEDANCE (Z) AT VARIOUS CONCENTRATIONS
OF IODINE - PARA CRESOL SYSTEM
Solvent : chloroform
Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 983.4 1278.2 6.04 0.81 13.1 35.8 0.6 3598 34.0 12.6
0.002 976.8 1278.7 6.05 0.82 13.3 21.8 0.6 3614 34.2 12.5
0.004 972.4 1279.5 6.06 0.83 13.6 12.3 0.6 3627 34.3 12.4
0.006 959.6 1279.7 6.06 0.85 14.1 -14.4 0.6 3649 34.5 12.3
0.010 962.8 1279.9 6.07 0.84 14.0 -8.3 0.6 3646 34.5 12.3
0.015 969.6 1279.5 6.04 0.83 13.6 5.0 0.6 3620 34.3 12.4
0.020 964.4 1279.8 6.02 0.84 13.8 -6.4 0.6 3623 34.3 12.3
Plots : Fig. 7.7 U vs Concentration; Fig. 7.9 χU vs Concentration; Fig. 7.11 CE vs Concentration;
Fig. 7.8 κ vs Concentration; Fig. 7.10 πi vs Concentration;
Page 213
213
TABLE 7.8
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE) AND ACOUSTIC IMPEDANCE (Z) AT VARIOUS CONCENTRATIONS
OF IODINE - META CRESOL SYSTEM
Solvent : chloroform
Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 970.0 1276.5 6.03 0.83 13.6 7.7 0.6 3615 34.3 12.4
0.002 973.2 1278.2 6.04 0.83 13.5 14.2 0.6 3616 34.2 12.4
0.004 971.6 1278.0 6.04 0.83 13.6 10.5 0.6 3619 34.3 12.4
0.006 960.8 1278.2 6.08 0.85 14.1 -12.1 0.6 3651 34.6 12.3
0.010 962.4 1278.6 6.13 0.84 14.1 -9.5 0.6 3660 34.6 12.3
0.015 964.4 1277.6 6.09 0.84 14.0 -6.2 0.6 3643 34.5 12.3
0.020 958.8 1279.3 6.02 0.85 14.0 -18.5 0.6 3634 34.4 12.3
Plots : Fig. 7.7 U vs Concentration; Fig. 7.9 χU vs Concentration; Fig. 7.11 CE vs Concentration;
Fig. 7.8 κ vs Concentration; Fig. 7.10 πi vs Concentration;
Page 214
214
TABLE 7.9
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE) AND ACOUSTIC IMPEDANCE (Z) AT VARIOUS CONCENTRATIONS
OF IODINE - PHENOL SYSTEM
Solvent : chloroform
Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 969.0 1278.5 6.04 0.83 13.6 5.6 0.6 3624 34.3 12.4
0.002 964.4 1278.2 6.09 0.84 14.0 -4.0 0.6 3647 34.5 12.3
0.004 968.4 1278.7 6.03 0.83 13.7 3.9 0.6 3623 34.3 12.4
0.006 965.6 1279.3 6.06 0.84 13.8 -2.2 0.6 3637 34.4 12.4
0.010 964.8 1279.2 6.11 0.84 14.0 -4.5 0.6 3653 34.6 12.3
0.015 967.2 1280.0 6.09 0.84 13.8 -0.4 0.6 3643 34.5 12.4
0.020 960.0 1280.5 6.06 0.85 14.1 -16.0 0.6 3646 34.5 12.3
Plots : Fig. 7.7 U vs Concentration; Fig. 7.9 χU vs Concentration; Fig. 7.11 CE vs Concentration;
Fig. 7.8 κ vs Concentration; Fig. 7.10 πi vs Concentration;
Page 215
215
TABLE 7.10
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE) AND ACOUSTIC IMPEDANCE (Z) AT VARIOUS CONCENTRATIONS
OF IODINE - CARVACROL SYSTEM
Solvent : chloroform
Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 964.8 1275.5 6.09 0.84 14.0 -3.1 0.6 3641 34.5 12.3
0.002 961.2 1276.5 6.08 0.85 14.1 -10.6 0.6 3648 34.6 12.3
0.004 957.4 1277.2 6.08 0.85 14.3 -18.7 0.6 3654 34.6 12.2
0.006 962.8 1278.4 6.09 0.84 14.0 -8.0 0.6 3648 34.5 12.3
0.010 968.4 1277.7 6.09 0.83 13.8 3.0 0.6 3635 34.4 12.4
0.015 957.0 1278.0 6.08 0.85 14.3 -21.2 0.6 3653 34.6 12.2
0.020 952.8 1278.2 6.06 0.86 14.4 -30.6 0.6 3652 34.6 12.2
Plots : Fig. 7.7 U vs Concentration; Fig. 7.9 χU vs Concentration; Fig. 7.11 CE vs Concentration;
Fig. 7.8 κ vs Concentration; Fig. 7.10 πi vs Concentration;
Page 216
216
TABLE 7.11
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE) AND ACOUSTIC IMPEDANCE (Z) AT VARIOUS CONCENTRATIONS
OF IODINE - ORTHO CRESOL SYSTEM
Solvent : carbon tetrachloride Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 894.4 1366.9 7.94 0.91 21.3 -25.5 0.6 3365 38.4 12.2
0.002 898.8 1367.6 7.96 0.91 21.1 -16.1 0.6 3362 38.3 12.3
0.004 896.8 1368.6 7.86 0.91 20.9 -20.9 0.6 3346 38.1 12.3
0.006 901.6 1367.0 7.91 0.90 20.8 -10.9 0.6 3345 38.1 12.3
0.010 898.4 1367.9 7.92 0.91 21.0 -18.9 0.6 3353 38.2 12.3
0.015 906.2 1368.1 7.93 0.89 20.5 -2.9 0.6 3342 38.1 12.4
0.020 907.6 1368.6 7.96 0.89 20.4 -1.1 0.6 3344 38.1 12.4
Plots : Fig. 7.11 U vs Concentration; Fig. 7.13 χU vs Concentration; Fig. 7.15 CE vs Concentration;
Fig. 7.12 κ vs Concentration; Fig. 7.14 πi vs Concentration;
Page 217
217
TABLE 7.12
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE) AND ACOUSTIC IMPEDANCE (Z) AT VARIOUS CONCENTRATIONS
OF IODINE - PARA CRESOL SYSTEM
Solvent : carbon tetrachloride Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 900.0 1365.8 8.10 0.90 21.4 -13.2 0.6 3386 38.6 12.3
0.002 901.2 1366.3 8.03 0.90 21.1 -10.7 0.6 3371 38.4 12.3
0.004 903.5 1366.5 7.98 0.90 20.8 -6.1 0.6 3355 38.3 12.3
0.006 905.2 1366.9 7.92 0.89 20.5 -2.7 0.6 3341 38.1 12.4
0.010 907.6 1367.2 7.96 0.89 20.5 1.8 0.6 3344 38.1 12.4
0.015 911.2 1367.3 8.00 0.88 20.3 8.8 0.6 3346 38.2 12.5
0.020 918.8 1367.0 8.04 0.87 19.9 24.7 0.6 3339 38.1 12.6
Plots : Fig. 7.11 U vs Concentration; Fig. 7.13 χU vs Concentration; Fig. 7.15 CE vs Concentration;
Fig. 7.12 κ vs Concentration; Fig. 7.14 πi vs Concentration;
Page 218
218
TABLE 7.13
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE) AND ACOUSTIC IMPEDANCE (Z) AT VARIOUS CONCENTRATIONS
OF IODINE - META CRESOL SYSTEM
Solvent : carbon tetrachloride Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 906.8 1366.5 8.00 0.89 20.6 1.8 0.6 3355 38.3 12.4
0.002 901.4 1367.2 7.95 0.90 20.9 -10.4 0.6 3355 38.2 12.3
0.004 898.0 1368.1 8.01 0.91 21.3 -18.3 0.6 3376 38.5 12.3
0.006 901.2 1369.2 7.96 0.90 20.9 -11.7 0.6 3360 38.2 12.3
0.010 898.0 1369.6 8.00 0.91 21.2 -19.7 0.6 3374 38.4 12.3
0.015 899.2 1368.8 7.98 0.90 21.1 -18.2 0.6 3367 38.3 12.3
0.020 896.8 1369.1 7.97 0.91 21.2 -24.6 0.6 3368 38.4 12.3
Plots : Fig. 7.11 U vs Concentration; Fig. 7.13 χU vs Concentration; Fig. 7.15 CE vs Concentration;
Fig. 7.12 κ vs Concentration; Fig. 7.14 πi vs Concentration;
Page 219
219
TABLE 7.14
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE) AND ACOUSTIC IMPEDANCE (Z) AT VARIOUS CONCENTRATIONS
OF IODINE - PHENOL SYSTEM
Solvent : carbon tetrachloride Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 914.2 1364.7 7.87 0.88 19.9 18.2 0.6 3311 37.8 12.5
0.002 906.8 1365.0 7.83 0.89 20.2 1.5 0.6 3316 37.9 12.4
0.004 912.8 1366.3 7.82 0.88 19.8 14.3 0.6 3306 37.7 12.5
0.006 911.2 1366.9 7.84 0.88 19.9 10.3 0.6 3312 37.8 12.5
0.010 912.8 1367.3 7.87 0.88 19.9 12.9 0.6 3317 37.8 12.5
0.015 904.8 1375.3 7.85 0.89 20.3 -5.9 0.6 3339 37.8 12.4
0.020 916.0 1368.5 7.86 0.87 19.7 17.7 0.6 3310 37.7 12.5
Plots : Fig. 7.11 U vs Concentration; Fig. 7.13 χU vs Concentration; Fig. 7.15 CE vs Concentration;
Fig. 7.12 κ vs Concentration; Fig. 7.14 πi vs Concentration;
Page 220
220
TABLE 7.15
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE) AND ACOUSTIC IMPEDANCE (Z) AT VARIOUS CONCENTRATIONS
OF IODINE - CARVACROL SYSTEM
Solvent : carbon tetrachloride Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 907.2 1365.3 7.96 0.89 20.5 2.6 0.6 3343 38.2 12.4
0.002 901.2 1366.3 7.89 0.90 20.7 -10.8 0.6 3340 38.1 12.3
0.004 909.6 1365.8 7.91 0.88 20.2 7.3 0.6 3328 38.0 12.4
0.006 907.2 1367.2 8.05 0.89 20.7 1.5 0.6 3364 38.4 12.4
0.010 908.0 1366.7 8.04 0.89 20.6 2.4 0.6 3357 38.3 12.4
0.015 901.6 1366.6 7.95 0.90 20.9 -12.8 0.6 3351 38.2 12.3
0.020 896.8 1367.3 8.02 0.91 21.4 -24.4 0.6 3374 38.5 12.3
Plots : Fig. 7.11 U vs Concentration; Fig. 7.13 χU vs Concentration; Fig. 7.15 CE vs Concentration;
Fig. 7.12 κ vs Concentration; Fig. 7.14 πi vs Concentration;
Page 221
221
TABLE 7.16
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE) AND ACOUSTIC IMPEDANCE (Z) AT VARIOUS CONCENTRATIONS
OF IODINE - ORTHO CRESOL SYSTEM
Solvent : n-hexane Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 1061.6 571.5 3.01 1.55 11.6 6.0 0.8 2088 31.9 6.1
0.002 1055.2 572.2 3.03 1.57 11.8 -6.3 0.8 2103 32.1 6.0
0.004 1049.2 572.7 3.02 1.59 12.0 -17.9 0.8 2106 32.1 6.0
0.006 1048.4 573.3 3.02 1.59 12.0 -19.8 0.8 2109 32.2 6.0
0.010 1052.0 574.2 3.02 1.57 11.9 -13.9 0.8 2102 32.1 6.0
0.015 1050.0 575.5 3.03 1.58 11.9 -18.6 0.8 2107 32.1 6.0
0.020 1052.8 576.7 3.04 1.56 11.9 -14.4 0.8 2108 32.1 6.1
Plots : Fig. 7.16 U vs Concentration; Fig. 7.18 χU vs Concentration; Fig. 7.20 CE vs Concentration;
Fig. 7.17 κ vs Concentration; Fig. 7.19 πi vs Concentration;
Page 222
222
TABLE 7.17
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE) AND ACOUSTIC IMPEDANCE (Z) AT VARIOUS CONCENTRATIONS
OF IODINE - PARA CRESOL SYSTEM
Solvent : n-hexane Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 1057.0 572.7 3.00 1.56 11.6 -2.6 0.8 2092 31.9 6.1
0.002 1050.8 572.2 2.99 1.58 11.8 -14.4 0.8 2094 32.0 6.0
0.004 1052.0 572.4 3.00 1.58 11.8 -12.5 0.8 2095 32.0 6.0
0.006 1050.4 573.0 3.02 1.58 12.0 -15.8 0.8 2106 32.1 6.0
0.010 1049.6 574.1 3.02 1.58 12.0 -17.8 0.8 2106 32.1 6.0
0.015 1048.0 575.0 3.01 1.58 12.0 -21.6 0.8 2101 32.0 6.0
0.020 1052.6 575.7 3.04 1.57 11.9 -13.7 0.8 2105 32.1 6.1
Plots : Fig. 7.16 U vs Concentration; Fig. 7.18 χU vs Concentration; Fig. 7.20 CE vs Concentration;
Fig. 7.17 κ vs Concentration; Fig. 7.19 πi vs Concentration;
Page 223
223
TABLE 7.18
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE) AND ACOUSTIC IMPEDANCE (Z) AT VARIOUS CONCENTRATIONS
OF IODINE - META CRESOL SYSTEM
Solvent : n-hexane Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 1045.6 567.6 2.96 1.61 12.0 -24.0 0.8 2078 32.0 5.9
0.002 1043.8 567.9 2.98 1.62 12.1 -27.6 0.8 2088 32.1 5.9
0.004 1048.0 568.9 2.97 1.60 11.9 -20.1 0.8 2079 31.9 6.0
0.006 1046.2 570.3 2.98 1.60 12.0 -23.9 0.8 2087 32.0 6.0
0.010 1049.2 572.3 3.00 1.59 11.9 -19.0 0.8 2095 32.1 6.0
0.015 1055.2 574.7 3.02 1.56 11.8 -8.8 0.8 2097 32.0 6.1
0.020 1056.8 576.6 3.04 1.55 11.7 -6.7 0.8 2103 32.0 6.1
Plots : Fig. 7.16 U vs Concentration; Fig. 7.18 χU vs Concentration; Fig. 7.20 CE vs Concentration;
Fig. 7.17 κ vs Concentration; Fig. 7.19 πi vs Concentration;
Page 224
224
TABLE 7.19
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE) AND ACOUSTIC IMPEDANCE (Z) AT VARIOUS CONCENTRATIONS
OF IODINE - PHENOL SYSTEM
Solvent : n-hexane Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 1053.2 572.5 3.00 1.57 11.8 -9.8 0.8 2098 32.0 6.0
0.002 1056.4 573.3 3.03 1.56 11.8 -4.0 0.8 2105 32.1 6.1
0.004 1054.4 573.7 3.05 1.57 11.9 -8.1 0.8 2116 32.2 6.0
0.006 1058.8 574.3 3.05 1.55 11.8 -0.2 0.8 2110 32.1 6.1
0.010 1052.2 575.4 3.04 1.57 11.9 -13.4 0.8 2114 32.2 6.1
0.015 1050.0 576.3 3.02 1.57 11.9 -18.5 0.8 2108 32.1 6.1
0.020 1049.1 577.1 3.03 1.57 11.9 -21.1 0.8 2110 32.1 6.1
Plots : Fig. 7.16 U vs Concentration; Fig. 7.18 χU vs Concentration; Fig. 7.20 CE vs Concentration;
Fig. 7.17 κ vs Concentration; Fig. 7.19 πi vs Concentration;
Page 225
225
TABLE 7.20
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE) AND ACOUSTIC IMPEDANCE (Z) AT VARIOUS CONCENTRATIONS
OF IODINE - CARVACROL SYSTEM
Solvent : n-hexane Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 1046.8 568.9 2.95 1.60 11.9 -21.8 0.8 2076 31.9 6.0
0.002 1048.4 570.0 2.99 1.60 12.0 -19.0 0.8 2090 32.0 6.0
0.004 1044.0 570.7 3.00 1.61 12.1 -27.6 0.8 2098 32.1 6.0
0.006 1042.6 571.0 2.98 1.61 12.1 -30.5 0.8 2092 32.1 6.0
0.010 1048.0 571.6 2.99 1.59 12.0 -21.2 0.8 2090 32.0 6.0
0.015 1057.2 573.5 3.01 1.56 11.7 -4.8 0.8 2086 31.9 6.1
0.020 1059.6 575.7 3.02 1.55 11.6 -1.2 0.8 2091 31.9 6.1
Plots : Fig. 7.16 U vs Concentration; Fig. 7.18 χU vs Concentration; Fig. 7.20 CE vs Concentration;
Fig. 7.17 κ vs Concentration; Fig. 7.19 πi vs Concentration;
Page 226
226
TABLE 7.21
MEAN VALUES OF RELAXATION TIME (ττττ), MEAN VALUES OF GIBB'S FREE ENERGY OF FORMATION (∆G) AND MEAN VALUES OF
FORMATION CONSTANT (K) FOR IODINE - PHENOLS CHARGE TRANSFER COMPLEXES IN DIFFERENT SOLVENTS AT 303 K
Solvent :- Dichloromethane Chloroform Carbon tetrachloride n-Hexane
ττττ /10-13 ∆G K ττττ /10-13 ∆G K ττττ /10-13 ∆G K ττττ /10-13 ∆G K
DONOR s
kJ mol-1 dm-3 mol-1 s
kJ mol-1 dm-3 mol-1 s
kJ mol-1 dm-3 mol-1 s
kJ mol-1 dm-3 mol-1
o-Cresol 5.4 -11.6 102.7 6.8 -10.6 71.0 9.5 -9.7 50.9 6.3 -8.6 32.8
p-Cresol 5.4 -11.2 90.0 6.7 -10.6 69.5 9.5 -9.8 49.2 6.3 -8.4 28.7
m-Cresol 5.3 -11.2 84.7 6.8 -10.4 65.1 9.6 -9.7 48.2 6.4 -8.1 27.0
Phenol 5.3 -10.9 82.1 6.8 -10.0 56.9 9.2 -9.5 45.0 6.3 -7.9 23.0
Carvacrol 5.3 -10.8 77.7 6.9 -9.9 54.6 9.5 -9.0 36.4 6.3 -7.0 15.8
Page 227
227
TABLE 7.22
FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi)
AND COHESIVE ENERGY (CE) FOR PURE LIQUIDS
COMPONENT ττττ /10-13 Lf ππππi CE
s Ao atm kJ mol-1
Dichloromethane 4.91 0.52 5017 32.6
Chloroform 6.74 0.54 4271 35.1
Carbon tetrachloride 9.46 0.55 4004 39.2
n-Hexane 6.23 0.73 2481 32.7
o-Cresol 27.21 0.41 8081 84.4
p-Cresol 12.15 0.48 4909 52.0
m-Cresol 51.63 0.42 10844 114.8
Phenol 26.02 0.42 9393 83.6
Carvacrol 83.29 0.45 8614 134.4
Page 228
Fig. 7.1 Plots of Ultrasonic velocity vs Concentration
1035
1045
1055
1065
0.000 0.005 0.010 0.015 0.020 0.025
Concentration, M
U,
m s
-1
IO-OCL IO-PCLIO-MCL IO-PLIO-CVL
Solvent : dichloromethane Temperature : 303 K
Fig. 7.2 Plots of Adiabatic compressibility vs Concentration
0.78
0.79
0.80
0.81
0.82
0.000 0.005 0.010 0.015 0.020 0.025
Concentration, M
κκ κκ /
10
-9,
kg
-1m
s2
IO-OCL IO-PCL IO-MCL
IO-PL IO-CVL
Solvent : dichloromethane Temperature : 303 K
Page 229
229
Fig. 7.3 Plots of Molecular interaction parameter vs Concentration
-30.0
-20.0
-10.0
0.0
10.0
20.0
0.000 0.005 0.010 0.015 0.020 0.025
Concentration, M
χχ χχU/1
0-3
, m
s-1
IO-OCL IO-PCLIO-MCL IO-PLIO-CVL
Solvent : dichloromethane Temperature : 303 K
Fig. 7.4 Plots of Internal pressure vs Concentration
4320
4340
4360
4380
4400
4420
0.000 0.005 0.010 0.015 0.020 0.025
Concentration, M
ππ ππi, a
tm
IO-OCL IO-PCL IO-MCLIO-PL IO-CVL
Solvent : dichloromethane Temperature : 303 K
Page 230
230
Fig. 7.5 Plots of Cohessive energy vs Concentration
32.6
32.8
33.0
33.2
33.4
0.000 0.005 0.010 0.015 0.020 0.025
Concentration, M
CE
, kJ m
ol-1
IO-OCL IO-PCL IO-MCL
IO-PL IO-CVL
Solvent : dichloromethane Temperature : 303 K
Fig. 7.6 Plots of Ultrasonic velocity vs Concentration
940
950
960
970
980
990
0.000 0.005 0.010 0.015 0.020 0.025
Concentration, M
U,
m s
-1
IO-OCL IO-PCLIO-MCL IO-PLIO-CVL
Solvent : chloroform Temperature : 303 K
Page 231
231
Fig. 7.7 Plots of Adiabatic compressibility vs Concentration
0.80
0.82
0.84
0.86
0.88
0.000 0.005 0.010 0.015 0.020 0.025
Concentration, M
κκ κκ /
10
-9,
kg
-1m
s2
IO-OCL IO-PCL IO-MCL
IO-PL IO-CVL
Solvent : chloroform Temperature : 303 K
Fig. 7.8 Plots of Molecular interaction parameter vs Concentration
-40.0
-20.0
0.0
20.0
40.0
0.000 0.005 0.010 0.015 0.020 0.025
Concentration, M
χχ χχU/1
0-3
, m
s-1
IO-OCL IO-PCLIO-MCL IO-PLIO-CVL
Solvent : chloroform Temperature : 303 K
Page 232
232
Fig. 7.9 Plots of Internal pressure vs Concentration
3580
3600
3620
3640
3660
3680
0.000 0.005 0.010 0.015 0.020 0.025
Concentration, M
ππ ππi, a
tm
IO-OCL IO-PCL IO-MCLIO-PL IO-CVL
Solvent : chloroform Temperature : 303 K
Fig. 7.10 Plots of Cohessive energy vs Concentration
34.0
34.2
34.4
34.6
34.8
0.000 0.005 0.010 0.015 0.020 0.025
Concentration, M
CE
, kJ m
ol-1
IO-OCL IO-PCL IO-MCL
IO-PL IO-CVL
Solvent : chloroform Temperature : 303 K
Page 233
233
Fig. 7.11 Plots of Ultrasonic velocity vs Concentration
890
900
910
920
0.000 0.005 0.010 0.015 0.020 0.025
Concentration, M
U,
m s
-1
IO-OCL IO-PCLIO-MCL IO-PLIO-CVL
Solvent : carbon tetrachloride Temperature : 303 K
Fig. 7.12 Plots of Adiabatic compressibility vs Concentration
0.86
0.87
0.88
0.89
0.90
0.91
0.92
0.000 0.005 0.010 0.015 0.020 0.025
Concentration, M
κκ κκ /
10
-9,
kg
-1m
s2
IO-OCL IO-PCL IO-MCL
IO-PL IO-CVL
Solvent : carbon tetrachloride Temperature : 303 K
Page 234
234
Fig. 7.13 Plots of Molecular interaction parameter vs Concentration
-30.0
-20.0
-10.0
0.0
10.0
20.0
30.0
0.000 0.005 0.010 0.015 0.020 0.025
Concentration, M
χχ χχU/1
0-3
, m
s-1
IO-OCL IO-PCLIO-MCL IO-PLIO-CVL
Solvent : carbon tetrachloride Temperature : 303 K
Fig. 7.14 Plots of Internal pressure vs Concentration
3300
3320
3340
3360
3380
3400
0.000 0.005 0.010 0.015 0.020 0.025
Concentration, M
ππ ππi, a
tm
IO-OCL IO-PCL IO-MCLIO-PL IO-CVL
Solvent : carbon tetrachloride Temperature : 303 K
Page 235
235
Fig. 7.15 Plots of Cohessive energy vs Concentration
37.6
37.8
38.0
38.2
38.4
38.6
38.8
0.000 0.005 0.010 0.015 0.020 0.025
Concentration, M
CE
, kJ m
ol-1
IO-OCL IO-PCL IO-MCL
IO-PL IO-CVL
Solvent : carbon tetrachloride Temperature : 303 K
Fig. 7.16 Plots of Ultrasonic velocity vs Concentration
1040
1050
1060
0.000 0.005 0.010 0.015 0.020 0.025
Concentration, M
U,
m s
-1
IO-OCL IO-PCLIO-MCL IO-PLIO-CVL
Solvent : n-hexane Temperature : 303 K
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Fig. 7.17 Plots of Adiabatic compressibility vs Concentration
1.54
1.56
1.58
1.60
1.62
0.000 0.005 0.010 0.015 0.020 0.025
Concentration, M
κκ κκ /
10
-9,
kg
-1m
s2
IO-OCL IO-PCLIO-MCL IO-PLIO-CVL
Solvent : n-hexane Temperature : 303 K
Fig. 7.18 Plots of Molecular interaction parameter vs Concentration
-35.0
-25.0
-15.0
-5.0
5.0
0.000 0.005 0.010 0.015 0.020 0.025
Concentration, M
χχ χχU/1
0-3
, m
s-1
IO-OCL IO-PCLIO-MCL IO-PLIO-CVL
Solvent : n-hexane Temperature : 303 K
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Fig. 7.19 Plots of Internal pressure vs Concentration
2070
2085
2100
2115
0.000 0.005 0.010 0.015 0.020 0.025
Concentration, M
ππ ππi, a
tm
IO-OCL IO-PCL IO-MCLIO-PL IO-CVL
Solvent : n-hexane Temperature : 303 K
Fig. 7.20 Plots of Cohessive energy vs Concentration
31.8
32.0
32.1
32.3
0.000 0.005 0.010 0.015 0.020 0.025
Concentration, M
CE
, kJ m
ol-1
IO-OCL IO-PCL IO-MCLIO-PL IO-CVL
Solvent : n-hexane Temperature : 303 K
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CHAPTER – 8
DETERMINATION OF STABILITY CONSTANTS FOR
CHARGE TRANSFER COMPLEXES OF IODINE MONOCHLORIDE AND CERTAIN PHENOLS AT 303 K
Introduction
The chemistry of phenolic group plays essential role in organic
synthesis as a pivotal functional group useful in a number of
transformations1-3. Phenols possess antifungal and antiviral properties and
they are used as effective antiseptic and disinfectant at low concentration4.
Halogens (X2) and interhalogen compounds (X-Y) form donor-acceptor
complexes of the type B…... X2 and B……XY with a wide range of Lewis
bases B5-7. These charge transfer (CT) complexes, first proposed by
Mulliken8 are now recognized to play a key role in many chemical and
biological processes. Consequently, many studies in spectral,
thermodynamic and other aspects have been reported in the literature, but
a few of them include a theoretical analysis of the results5,6,9. Although the
CT complexes are formed to be stable in solvents of low dielectric constants,
there is need for further work on the role of solvent in determining the
stability of CT complexes. Phenols form donor-acceptor complexes with
halogens, 2,3-dichloro-4,5dicyano-p-benzoquinone10 (DDQ),
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tetracyanoethylene11 (TCN) and chloronil12 Kirsch et al have studied the
structure of these complexes by 1R studies11,12.
This chapter contains the results obtained in the ultrasonic
investigation of CT complexes formed between iodine monochloride and five
phenols. Studies are made in four different less polar and non polar
solvents, namely, dichloromethane, chloroform, carbon tetrachloride and n-
hexane. Ultrasonic velocities, densities and viscosities are measured in
solutions containing equimolar concentrations of phenol (donor) and iodine
mono-chloride (acceptor). Acoustical parameters such as adiabatic
compressibility, free length, internal pressure, cohesive energy and acoustic
impedance values are calculated from the measured properties. The
measurements and calculations have been made in order to establish the
formation of CT complex between iodine monochloride and phenol. In order
to asses the attraction between the donor and acceptor, formation constants
of the complexes are calculated using the equation proposed by
Kannappan13,14. This method is better than Bhatt’s15 method as the latter
can be used only for systems in which strong CT complexes are formed in
binary systems.
The measured ultrasonic velocities for the twenty systems along with
other acoustical properties are listed in Tables 8.1 – 8.20. Fig. 8.1 contains
the plots of ultrasonic velocity vs concentration for the five systems in
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dichloromethane solution. It is found that the ultrasonic velocity decreases
with concentration, reaches a minimum at a specific concentration and then
increases with increase in concentration. A similar trend is observed in all
the media (Figs. 8.6, 8.11 and 8.16). These observations indicate that there
are interactions between iodine monochloride and phenol molecules even in
dilute solution. The interaction is found to be the maximum at a specific
concentration, which is characteristic of the solvent. This is also supported
by the increase in density with concentration in dilute solution. The density
is also higher at a characteristic concentration. At this concentration, the
viscosity is also found to be high.
Adiabatic compressibility (κ) values are calculated for the twenty
systems from the measured ultrasonic velocity and density values. Plots of
adiabatic compressibility against concentration in dichloromethane solvent
are given in Fig. 8.2. Similar plots for other solvents are given in Figs. 8.7,
8.12 and 8.17. The trend in adiabatic compressibility values with
concentration is the reverse of the trend observed in velocity values.
Adiabatic compressibility is found to be high at the concentration at which
the extent of complexation is a maximum. The increase in adiabatic
compressibility at a specific concentration also establishes the formation of
a CT complex between iodine monochloride and phenol. This is also
supported by the observation that free length values in the systems are
different from those in pure components (Chapter 7, Table 7.22). It is seen
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242
that the free length is found to be constant for a given system. The values
are slightly greater than those of pure components. This confirms the
formation CT complexes between iodine monochloride and phenols.
Acoustic impedance (Z) is indicative of repulsive forces between the
component molecules. These values are given for all the systems in
Tables 8.1 – 8.20. It is formed that the acoustic impedance varies only
slightly with concentration. The slight decrease in acoustic impedance in the
mixtures containing donor-acceptor establishes the presence of attractive
forces between iodine monochloride and phenol molecules. This confirms
the formation of CT complexes between iodine monochloride and phenols.
Molecular interaction parameters (χU) with respect to velocity are a
measure of deviation from ideal behaviour and it can be used to establish
the formation of CT complexes. In the present investigation, molecular
interaction parameter values are calculated for all the systems at different
concentrations (Tables 8.1 – 8.20) and plots of molecular interaction
parameters against concentration are illustrated in Figs. 8.3, 8.8, 8.13 and
8.18. The positive and negative values of molecular interaction parameter in
almost all the systems establish the formation of CT complexes between
iodine monochloride and phenols in the four solvents investigated.
Molecular interaction parameter value is found to be large negative at a
specific concentration in each system. This observation also establishes that
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243
the extent of complexation depends upon concentration and it is maximum
at a characteristic concentration.
Internal pressure (πi) in binary and ternary liquid mixtures can be
used to assess the deviation from ideal behaviour which may arise due to
intermolecular forces. The values of internal pressure are calculated for all
the systems and plots of internal pressure vs concentration are given in
figures 8.4, 8.9, 8.14 and 8.19. It is found that the internal pressure values
in ternary mixtures are different from that in pure components (Chapter 7,
Table 7.22). This indicates that there is a deviation from ideal behaviour in
all the systems which may be due to the formation of CT complexes between
iodine monochloride and phenols. In each system, internal pressure value is
relatively high at a particular concentration, suggesting that the
complexation is maximum at a specific concentration. This concentration
depends upon the solvent. Thus, the stability of this type of complexes is
influenced by the nature of the solvent.
Cohesive energy (CE) is another acoustical parameter that can be
used to assess the intermolecular attraction and CT complex formation in
liquid mixtures. Cohesive energy values for the twenty systems are
calculated and presented in Tables 8.1 – 8.20. The variation of cohesive
energy with concentration depends upon the nature of components in the
ternary mixtures. However, cohesive energy is high at a specific
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244
concentration. Thus, intermolecular attraction in the systems studied is
maximum at that concentration. Plots of cohesive energy against
concentration for all the systems are illustrated in Figs. 8.5, 8.10, 8.15 and
8.20. Thus, the variation in the acoustical parameters establishes the
formation of a donor-acceptor complex between iodine monochloride and
phenols and the stability of the complex depends upon the concentration
and structure of phenols.
The effect of phenol structure and the influence of solvent on the
stability of the CT complex are also investigated in the present investigation.
The stability constants (K) of the complexes between iodine monochloride
and five structurally different phenols are calculated by the method of
Kannappan. The mean values of stability constant for the twenty systems in
four different solvents are summarised in Table 8.21. The change in the
values of stability constant with the structure of phenol is explained first.
The mean values of formation constant (Table 8.21) in a given solvent
suggest that the stability of complexes of iodine monochloride with phenols
is in the order:
Carvacrol < phenol < m-cresol < p-cresol < o-cresol
This order is the same as that between iodine and phenols. The presence of
methyl substituent at ortho and para positions of phenol, enhances the
stability of the complex as this substituent increases the π-electron density
of the benzene ring by inductive and hyper conjugative effects. In the case of
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m-cresol, only +I effect operates and hence, it forms a more stable complex
with iodine monochloride than with phenol. The stability constant of o-
cresol-iodine monochloride complex is greater than that of p-cresol-iodine
monochloride complex as the electron releasing methyl substituents in
o-cresol is near the complexation site. Carvacrol-iodine monochloride
complex is the least stable among the five systems. This may be due to
steric effect of the presence of both iso-propyl and methyl substituents near
the complexation site in the ring.
The CT complexes are generally stable in less polar solvents as polar
solvents will destabilize the complex due to solvation of donor and acceptor
molecules as these are also polar compounds. The formation constants are
calculated for iodine monochloride-phenol complexes in four different
solvents to study the influence of solvent on the stability of these complexes.
The data are presented in Table 8.21. It is found that for a given system, the
stability constant increases with increase in the dielectric constant of the
medium. Thus the stability constant of o-cresol-iodine monochloride is the
highest in dichloromethane which has a dielectric constant (ε) of about 9
while the stability constant is the least in n-hexane which has a dielectric
constant of 1.89. This trend can be explained as follows: Phenol is a dipolar
molecule and iodine monochloride is also a polar molecule. When iodine
monochloride forms CT complex with phenol, the donor molecule is further
polarised. The increase in polarization leads to greater solvation in a solvent
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246
of slightly higher dielectric constant and hence, among the less polar
solvents stability constant increases with increase in the dielectric constant
of the medium.
It is also worth comparing the stability constants of iodine monochloride-
phenol complexes (Table 8.21) with those of iodine-phenol complexes
(Chapter 7, Table 7.21). Comparison of the data presented in these two
tables shows that iodine forms a less stable complex with phenol than
iodine monochloride. This may be due to greater polarizing power of iodine
monochloride than that of iodine. Iodine monochloride is more polar than
iodine and it is a more effective Lewis acid than iodine. Another aspect
which is interesting to note is that the influence of methyl substituents in
phenol is more significant in iodine monochloride-phenol systems than in
iodine-phenol systems. This is better illustrated by comparing the difference
in the stability constants of iodine-phenol system and iodine-o-cresol
system and also by the difference between the stability constant values of
iodine monochloride-phenol and iodine monochloride-o-cresol systems. This
difference is more in the case of systems containing iodine than in the case
of systems containing iodine monochloride. This observation indicates the
extended selectivity relationship may be applicable to the complexation
process which involves equilibrium between donor and acceptor. This
principle was proposed by Brown and Nelson16,17 for electrophilic
substitution reaction which is a rate process. According to this principle,
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247
the more reactive the attacking species, the less selective in electrophilic
substitution. When partial rates are considered, the less reactive
electrophile is better in distinguishing the substrates with different rates
than the more reactive electrophile. In the present case, iodine is a less
effective acceptor than iodine monochloride. It is more effective in
distinguishing the stabilities of complexes with phenols which are
structurally different.
Page 248
248
REFERENCES
1. Carruthers, W., Some Modern Methods of Organic Synthesis, 3rd
Edn., Cambridge
University Press, Cambridge, 1984.
2. House, H.O., Modern Synthetic Methods, 2nd
Edn., Benjamin Cummins, Menlo Park,
1972.
3. March, J., Advanced Organic Chemistry, 4th
Edn., John Wiley, New York, 1992.
4. Francis A Carey, Organic Chemistry, 5th
Edn., Tata McGraw Hill Publishing
Comapany Ltd., New Delhi, 2005.
5. Legon, A.C., J. Chem. Soc., Faraday Trans., 91, 1995, 1881.
6. Raby, C., Claud, J., Buxereaud, J and Moesch, C., Bull. Soc. Chim. Fr., 1981, 5.
7. Drago, R.S. and Wenz, D.A., J. Am. Chem. Soc., 84, 1962, 526.
8. Mulliken, R.S., J. Am. Chem. Soc., 72, 1950, 600.
9. Abboud, J.L.M., Mo, O., de Paz, J.L.G., Yanez, M., Esseffar, M., Bouab, W., El
Mouhtadi, M., Mokhlisse, R., Ballesteros, E., Herreros, M., Homan, H., Lopez
Mardomingo, C. and Notario, R., J. Am. Chem. Soc., 115, 1993, 12468.
10. Vinodkumar, T, Veeraiah, T. and Venkateshwarlu, G., Proc. Indian Acad. Sci.
(Chem. Sci.), 112, 2000, 119.
11. Volkman, B., Kirsch, J., Proc. Ind. Acad. Sci., 97, 1988, 229.
12. Harsh, D. and Kirsch, J., Proc. Ind. Acad. Sci., 97, 1988, 223.
13. Kannappan, V. and Jaya Santhi, R., J. Acous. Soc. Ind., 29, 2001, 192.
14. Kannappan, V., Jaya Santhi, R. and Malar, E.J.P., Phys. Chem. Liq., 40(4), 2002, 507.
15. Marwein, B.L. and Bhatt, S.N., Acustica, 58, 1985, 243.
16. Brown, H.C. and McGray, C.W., J. Am. Chem. Soc., 77, 1955, 2300.
17. Brown, H.C. and Nelson, K.L., J. Am. Chem. Soc., 75, 1953, 6292.
Page 249
TABLE 8.1
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE) AND ACOUSTIC IMPEDANCE (Z) AT VARIOUS CONCENTRATIONS
OF IODINE MONOCHLORIDE - ORTHO CRESOL SYSTEM
Solvent : dichloromethane Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 1060.4 1136.7 5.10 0.78 9.9 13.7 0.6 4378 33.1 12.1
0.002 1050.0 1137.6 5.11 0.80 10.2 -6.2 0.6 4408 33.3 11.9
0.004 1049.0 1138.0 5.08 0.80 10.2 -8.1 0.6 4397 33.3 11.9
0.006 1048.0 1137.8 5.08 0.80 10.2 -10.1 0.6 4396 33.3 11.9
0.010 1052.0 1138.2 5.08 0.79 10.1 -2.7 0.6 4390 33.2 12.0
0.015 1056.0 1137.9 5.08 0.79 10.0 4.6 0.6 4379 33.2 12.0
0.020 1050.1 1138.4 5.09 0.80 10.2 -6.8 0.6 4394 33.3 12.0
Plots : Fig. 8.1 U vs Concentration; Fig. 8.3 χU vs Concentration; Fig. 8.5 CE vs Concentration;
Fig. 8.2 κ vs Concentration; Fig. 8.4 πi vs Concentration;
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TABLE 8.2
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE) AND ACOUSTIC IMPEDANCE (Z) AT VARIOUS CONCENTRATIONS
OF IODINE MONOCHLORIDE - PARA CRESOL SYSTEM
Solvent : dichloromethane Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 1055.2 1137.1 5.06 0.79 10.0 3.8 0.6 4374 33.1 12.0
0.002 1054.3 1137.9 5.07 0.79 10.0 2.1 0.6 4382 33.1 12.0
0.004 1049.9 1138.3 5.06 0.80 10.1 -6.3 0.6 4386 33.2 12.0
0.006 1048.0 1136.9 5.06 0.80 10.2 -10.0 0.6 4388 33.2 11.9
0.010 1050.2 1137.5 5.07 0.80 10.1 -5.9 0.6 4387 33.2 11.9
0.015 1058.8 1137.9 5.06 0.78 9.9 10.4 0.6 4365 33.0 12.0
0.020 1061.2 1138.0 5.04 0.78 9.7 14.9 0.6 4348 32.9 12.1
Plots : Fig. 8.1 U vs Concentration; Fig. 8.3 χU vs Concentration; Fig. 8.5 CE vs Concentration;
Fig. 8.2 κ vs Concentration; Fig. 8.4 πi vs Concentration;
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TABLE 8.3
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE) AND ACOUSTIC IMPEDANCE (Z) AT VARIOUS CONCENTRATIONS
OF IODINE MONOCHLORIDE - META CRESOL SYSTEM
Solvent : dichloromethane Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 1052.0 1137.8 5.03 0.79 10.0 -2.3 0.6 4372 33.1 12.0
0.002 1056.0 1138.1 5.04 0.79 9.9 5.2 0.6 4367 33.0 12.0
0.004 1062.8 1139.3 5.04 0.78 9.7 18.1 0.6 4357 32.9 12.1
0.006 1052.4 1139.0 5.05 0.79 10.0 -1.8 0.6 4378 33.1 12.0
0.010 1058.8 1138.5 5.05 0.78 9.8 10.2 0.6 4363 33.0 12.1
0.015 1058.0 1139.0 5.06 0.78 9.9 8.5 0.6 4370 33.0 12.1
0.020 1051.4 1140.4 5.08 0.79 10.1 -4.2 0.6 4393 33.2 12.0
Plots : Fig. 8.1 U vs Concentration; Fig. 8.3 χU vs Concentration; Fig. 8.5 CE vs Concentration;
Fig. 8.2 κ vs Concentration; Fig. 8.4 πi vs Concentration;
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252
TABLE 8.4
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE) AND ACOUSTIC IMPEDANCE (Z) AT VARIOUS CONCENTRATIONS
OF IODINE MONOCHLORIDE - PHENOL SYSTEM
Solvent : dichloromethane Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 1057.0 1136.9 5.04 0.79 9.9 7.2 0.6 4361 33.0 12.0
0.002 1055.0 1137.3 5.05 0.79 9.9 3.3 0.6 4372 33.1 12.0
0.004 1053.0 1139.0 5.05 0.79 10.0 -0.5 0.6 4379 33.1 12.0
0.006 1050.0 1139.1 5.07 0.80 10.1 -6.3 0.6 4393 33.2 12.0
0.010 1046.0 1139.3 5.07 0.80 10.2 -14.0 0.6 4403 33.3 11.9
0.015 1042.0 1139.3 5.04 0.81 10.3 -21.7 0.6 4393 33.2 11.9
0.020 1057.6 1140.0 5.02 0.78 9.8 7.6 0.6 4355 32.9 12.1
Plots : Fig. 8.1 U vs Concentration; Fig. 8.3 χU vs Concentration; Fig. 8.5 CE vs Concentration;
Fig. 8.2 κ vs Concentration; Fig. 8.4 πi vs Concentration;
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TABLE 8.5
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE) AND ACOUSTIC IMPEDANCE (Z) AT VARIOUS CONCENTRATIONS
OF IODINE MONOCHLORIDE - CARVACROL SYSTEM
Solvent : dichloromethane Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 1070.0 1138.4 5.06 0.77 9.5 32.1 0.5 4348 32.9 12.2
0.002 1056.0 1138.5 5.05 0.79 9.9 5.3 0.6 4373 33.1 12.0
0.004 1052.4 1139.4 5.05 0.79 10.0 -1.7 0.6 4381 33.1 12.0
0.006 1050.0 1139.5 5.06 0.80 10.1 -6.3 0.6 4391 33.2 12.0
0.010 1049.2 1139.5 5.08 0.80 10.1 -7.9 0.6 4396 33.2 12.0
0.015 1054.8 1140.1 5.10 0.79 10.0 2.5 0.6 4394 33.2 12.0
0.020 1057.1 1140.6 5.09 0.78 9.9 6.7 0.6 4384 33.1 12.1
Plots : Fig. 8.1 U vs Concentration; Fig. 8.3 χU vs Concentration; Fig. 8.5 CE vs Concentration;
Fig. 8.2 κ vs Concentration; Fig. 8.4 πi vs Concentration;
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254
TABLE 8.6
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE) AND ACOUSTIC IMPEDANCE (Z) AT VARIOUS CONCENTRATIONS
OF IODINE MONOCHLORIDE - ORTHO CRESOL SYSTEM
Solvent : chloroform
Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 971.4 1278.5 6.06 0.83 13.6 10.7 0.6 3627 34.3 12.4
0.002 962.6 1279.0 6.08 0.84 14.0 -7.6 0.6 3651 34.5 12.3
0.004 966.0 1276.8 6.10 0.84 13.9 -0.8 0.6 3646 34.5 12.3
0.006 965.2 1278.5 6.12 0.84 14.0 -2.6 0.6 3656 34.6 12.3
0.010 979.2 1276.4 6.11 0.82 13.4 26.2 0.6 3624 34.3 12.5
0.015 967.4 1279.2 6.09 0.84 13.8 1.1 0.6 3642 34.4 12.4
0.020 977.6 1279.6 6.01 0.82 13.2 21.9 0.6 3602 34.1 12.5
Plots : Fig. 8.6 U vs Concentration; Fig. 8.8 χU vs Concentration; Fig. 8.10 CE vs Concentration;
Fig. 8.7 κ vs Concentration; Fig. 8.9 πi vs Concentration;
Page 255
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TABLE 8.7
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE) AND ACOUSTIC IMPEDANCE (Z) AT VARIOUS CONCENTRATIONS
OF IODINE MONOCHLORIDE - PARA CRESOL SYSTEM
Solvent : chloroform
Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 971.3 1277.0 6.07 0.83 13.6 10.5 0.6 3627 34.4 12.4
0.002 972.0 1278.8 6.06 0.83 13.6 11.9 0.6 3626 34.3 12.4
0.004 975.2 1277.3 6.03 0.82 13.4 18.5 0.6 3608 34.2 12.5
0.006 968.8 1279.1 6.05 0.83 13.7 5.1 0.6 3629 34.3 12.4
0.010 960.0 1278.9 6.06 0.85 14.1 -13.3 0.6 3649 34.5 12.3
0.015 955.0 1278.7 6.04 0.86 14.3 -23.8 0.6 3650 34.5 12.2
0.020 949.2 1278.8 6.02 0.87 14.5 -35.9 0.6 3655 34.6 12.1
Plots : Fig. 8.6 U vs Concentration; Fig. 8.8 χU vs Concentration; Fig. 8.10 CE vs Concentration;
Fig. 8.7 κ vs Concentration; Fig. 8.9 πi vs Concentration;
Page 256
256
TABLE 8.8
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE) AND ACOUSTIC IMPEDANCE (Z) AT VARIOUS CONCENTRATIONS
OF IODINE MONOCHLORIDE - META CRESOL SYSTEM
Solvent : chloroform
Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 978.0 1277.0 6.16 0.82 13.6 24.5 0.6 3641 34.5 12.5
0.002 964.0 1278.0 6.11 0.84 14.0 -4.7 0.6 3656 34.6 12.3
0.004 962.8 1278.5 6.10 0.84 14.0 -7.4 0.6 3653 34.6 12.3
0.006 966.8 1279.1 6.07 0.84 13.8 0.7 0.6 3640 34.4 12.4
0.010 968.8 1279.0 6.08 0.83 13.7 4.5 0.6 3637 34.4 12.4
0.015 962.9 1279.3 6.09 0.84 14.0 -8.1 0.6 3651 34.5 12.3
0.020 961.2 1280.3 6.10 0.85 14.1 -12.0 0.6 3660 34.6 12.3
Plots : Fig. 8.6 U vs Concentration; Fig. 8.8 χU vs Concentration; Fig. 8.10 CE vs Concentration;
Fig. 8.7 κ vs Concentration; Fig. 8.9 πi vs Concentration;
Page 257
257
TABLE 8.9
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE) AND ACOUSTIC IMPEDANCE (Z) AT VARIOUS CONCENTRATIONS
OF IODINE MONOCHLORIDE - PHENOL SYSTEM
Solvent : chloroform
Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 960.0 1277.3 6.04 0.85 14.1 -12.9 0.6 3640 34.5 12.3
0.002 962.0 1278.7 6.06 0.85 14.0 -8.8 0.6 3646 34.5 12.3
0.004 980.6 1279.3 6.09 0.81 13.3 29.7 0.6 3619 34.2 12.5
0.006 995.0 1279.8 6.06 0.79 12.6 60.0 0.6 3586 33.9 12.7
0.010 982.0 1280.3 6.03 0.81 13.1 32.1 0.6 3601 34.0 12.6
0.015 974.8 1279.6 6.00 0.82 13.3 16.6 0.6 3604 34.1 12.5
0.020 973.6 1279.0 5.98 0.82 13.3 13.7 0.6 3599 34.0 12.5
Plots : Fig. 8.6 U vs Concentration; Fig. 8.8 χU vs Concentration; Fig. 8.10 CE vs Concentration;
Fig. 8.7 κ vs Concentration; Fig. 8.9 πi vs Concentration;
Page 258
258
TABLE 8.10
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE) AND ACOUSTIC IMPEDANCE (Z) AT VARIOUS CONCENTRATIONS
OF IODINE MONOCHLORIDE - CARVACROL SYSTEM
Solvent : chloroform
Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 977.6 1277.4 6.03 0.82 13.3 23.7 0.6 3603 34.1 12.5
0.002 973.2 1278.3 6.05 0.83 13.5 14.4 0.6 3619 34.2 12.4
0.004 971.2 1278.5 6.07 0.83 13.6 10.1 0.6 3629 34.3 12.4
0.006 964.4 1278.4 6.06 0.84 13.9 -4.2 0.6 3638 34.4 12.3
0.010 966.4 1278.2 6.06 0.84 13.8 -0.4 0.6 3634 34.4 12.4
0.015 963.2 1278.6 6.05 0.84 13.9 -7.4 0.6 3635 34.4 12.3
0.020 978.8 1278.2 6.04 0.82 13.2 24.7 0.6 3602 34.1 12.5
Plots : Fig. 8.6 U vs Concentration; Fig. 8.8 χU vs Concentration; Fig. 8.10 CE vs Concentration;
Fig. 8.7 κ vs Concentration; Fig. 8.9 πi vs Concentration;
Page 259
259
TABLE 8.11
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE) AND ACOUSTIC IMPEDANCE (Z) AT VARIOUS CONCENTRATIONS
OF IODINE MONOCHLORIDE - ORTHO CRESOL SYSTEM
Solvent : carbon tetrachloride Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 913.8 1368.8 7.99 0.87 20.1 17.4 0.6 3342 38.0 12.5
0.002 898.0 1368.6 7.94 0.91 21.1 -17.6 0.6 3361 38.3 12.3
0.004 911.6 1369.2 7.95 0.88 20.1 12.1 0.6 3339 38.0 12.5
0.006 907.4 1369.1 7.96 0.89 20.5 2.5 0.6 3351 38.1 12.4
0.010 905.6 1368.3 7.94 0.89 20.5 -2.1 0.6 3347 38.1 12.4
0.015 896.8 1369.0 7.93 0.91 21.1 -22.1 0.6 3363 38.3 12.3
0.020 895.6 1370.1 7.99 0.91 21.3 -25.4 0.6 3381 38.4 12.3
Plots : Fig. 8.11 U vs Concentration; Fig. 8.13 χU vs Concentration; Fig. 8.15 CE vs Concentration;
Fig. 8.12 κ vs Concentration; Fig. 8.14 πi vs Concentration;
Page 260
260
TABLE 8.12
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE) AND ACOUSTIC IMPEDANCE (Z) AT VARIOUS CONCENTRATIONS
OF IODINE MONOCHLORIDE - PARA CRESOL SYSTEM
Solvent : carbon tetrachloride Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 919.0 1365.9 7.90 0.87 19.6 29.0 0.6 3311 37.8 12.6
0.002 920.8 1367.6 7.93 0.86 19.5 33.0 0.6 3315 37.8 12.6
0.004 897.2 1367.8 7.95 0.91 21.1 -19.5 0.6 3363 38.3 12.3
0.006 902.8 1367.7 7.96 0.90 20.8 -7.4 0.6 3356 38.2 12.3
0.010 904.0 1368.8 7.98 0.89 20.8 -5.1 0.6 3361 38.2 12.4
0.015 902.3 1366.1 7.97 0.90 20.9 -9.3 0.6 3358 38.3 12.3
0.020 905.2 1367.3 7.98 0.89 20.7 -3.4 0.6 3357 38.2 12.4
Plots : Fig. 8.11 U vs Concentration; Fig. 8.13 χU vs Concentration; Fig. 8.15 CE vs Concentration;
Fig. 8.12 κ vs Concentration; Fig. 8.14 πi vs Concentration;
Page 261
261
TABLE 8.13
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE) AND ACOUSTIC IMPEDANCE (Z) AT VARIOUS CONCENTRATIONS
OF IODINE MONOCHLORIDE - META CRESOL SYSTEM
Solvent : carbon tetrachloride Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 916.3 1366.9 7.98 0.87 19.9 23.0 0.6 3333 38.0 12.5
0.002 913.2 1368.8 7.96 0.88 20.1 15.9 0.6 3337 38.0 12.5
0.004 905.4 1369.6 7.93 0.89 20.5 -1.6 0.6 3348 38.1 12.4
0.006 901.5 1369.0 7.94 0.90 20.8 -10.5 0.6 3356 38.2 12.3
0.010 900.4 1369.6 7.95 0.90 20.9 -13.4 0.6 3362 38.2 12.3
0.015 904.0 1369.1 7.96 0.89 20.7 -6.2 0.6 3356 38.2 12.4
0.020 896.5 1368.3 7.96 0.91 21.2 -23.3 0.6 3371 38.4 12.3
Plots : Fig. 8.11 U vs Concentration; Fig. 8.13 χU vs Concentration; Fig. 8.15 CE vs Concentration;
Fig. 8.12 κ vs Concentration; Fig. 8.14 πi vs Concentration;
Page 262
262
TABLE 8.14
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE) AND ACOUSTIC IMPEDANCE (Z) AT VARIOUS CONCENTRATIONS
OF IODINE MONOCHLORIDE - PHENOL SYSTEM
Solvent : carbon tetrachloride Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 900.0 1366.5 7.97 0.90 21.0 -13.1 0.6 3362 38.3 12.3
0.002 901.2 1368.3 7.98 0.90 21.0 -10.6 0.6 3364 38.3 12.3
0.004 905.8 1368.5 7.98 0.89 20.6 -0.7 0.6 3356 38.2 12.4
0.006 915.2 1369.6 7.97 0.87 20.0 19.8 0.6 3338 38.0 12.5
0.010 918.4 1369.4 7.95 0.87 19.7 26.4 0.6 3329 37.9 12.6
0.015 924.2 1368.3 7.95 0.86 19.3 38.8 0.6 3317 37.8 12.6
0.020 902.4 1369.1 7.95 0.90 20.8 -10.3 0.6 3359 38.2 12.4
Plots : Fig. 8.11 U vs Concentration; Fig. 8.13 χU vs Concentration; Fig. 8.15 CE vs Concentration;
Fig. 8.12 κ vs Concentration; Fig. 8.14 πi vs Concentration;
Page 263
263
TABLE 8.15
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE) AND ACOUSTIC IMPEDANCE (Z) AT VARIOUS CONCENTRATIONS
OF IODINE MONOCHLORIDE - CARVACROL SYSTEM
Solvent : carbon tetrachloride Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 909.2 1367.3 7.93 0.88 20.3 7.2 0.6 3337 38.0 12.4
0.002 915.2 1368.8 8.01 0.87 20.1 20.4 0.6 3344 38.1 12.5
0.004 916.0 1368.9 7.97 0.87 19.9 21.9 0.6 3336 38.0 12.5
0.006 911.8 1368.7 7.93 0.88 20.1 12.3 0.6 3333 37.9 12.5
0.010 910.9 1367.6 7.94 0.88 20.2 9.8 0.6 3336 38.0 12.5
0.015 901.2 1367.7 7.96 0.90 20.9 -12.2 0.6 3358 38.3 12.3
0.020 910.0 1368.0 7.96 0.88 20.3 6.6 0.6 3343 38.1 12.4
Plots : Fig. 8.11 U vs Concentration; Fig. 8.13 χU vs Concentration; Fig. 8.15 CE vs Concentration;
Fig. 8.12 κ vs Concentration; Fig. 8.14 πi vs Concentration;
Page 264
264
TABLE 8.16
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE) AND ACOUSTIC IMPEDANCE (Z) AT VARIOUS CONCENTRATIONS
OF IODINE MONOCHLORIDE - ORTHO CRESOL SYSTEM
Solvent : n-hexane Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 1060.0 571.2 2.99 1.56 11.5 3.1 0.8 2083 31.8 6.1
0.002 1053.8 571.0 3.00 1.58 11.8 -8.7 0.8 2092 32.0 6.0
0.004 1056.8 571.1 3.00 1.57 11.7 -3.2 0.8 2089 32.0 6.0
0.006 1062.0 570.7 2.99 1.55 11.5 6.5 0.8 2080 31.8 6.1
0.010 1056.0 570.5 2.98 1.57 11.7 -5.2 0.8 2079 31.9 6.0
0.015 1043.2 570.2 2.97 1.61 12.1 -29.6 0.8 2086 32.0 5.9
0.020 1048.4 569.6 2.96 1.60 11.8 -20.3 0.8 2073 31.9 6.0
Plots : Fig. 8.16 U vs Concentration; Fig. 8.18 χU vs Concentration; Fig. 8.20 CE vs Concentration;
Fig. 8.17 κ vs Concentration; Fig. 8.19 πi vs Concentration;
Page 265
265
TABLE 8.17
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE) AND ACOUSTIC IMPEDANCE (Z) AT VARIOUS CONCENTRATIONS
OF IODINE MONOCHLORIDE - PARA CRESOL SYSTEM
Solvent : n-hexane Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 1045.4 571.0 2.97 1.60 12.0 -24.3 0.8 2091 32.0 6.0
0.002 1052.4 571.2 2.98 1.58 11.8 -11.2 0.8 2087 31.9 6.0
0.004 1055.6 571.2 2.99 1.57 11.7 -5.2 0.8 2087 31.9 6.0
0.006 1050.4 571.5 2.99 1.59 11.9 -15.1 0.8 2091 32.0 6.0
0.010 1052.8 571.5 2.99 1.58 11.8 -10.7 0.8 2089 32.0 6.0
0.015 1060.8 570.6 2.98 1.56 11.5 4.2 0.8 2073 31.8 6.1
0.020 1065.8 570.3 2.97 1.54 11.3 13.5 0.8 2064 31.7 6.1
Plots : Fig. 8.16 U vs Concentration; Fig. 8.18 χU vs Concentration; Fig. 8.20 CE vs Concentration;
Fig. 8.17 κ vs Concentration; Fig. 8.19 πi vs Concentration;
Page 266
266
TABLE 8.18
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE) AND ACOUSTIC IMPEDANCE (Z) AT VARIOUS CONCENTRATIONS
OF IODINE MONOCHLORIDE - META CRESOL SYSTEM
Solvent : n-hexane Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 1053.4 571.1 2.97 1.58 11.7 -9.3 0.8 2083 31.8 6.0
0.002 1053.6 571.0 2.94 1.58 11.6 -9.0 0.8 2073 31.7 6.0
0.004 1051.2 571.2 2.93 1.58 11.6 -13.7 0.8 2070 31.7 6.0
0.006 1049.6 571.0 2.98 1.59 11.9 -16.8 0.8 2088 32.0 6.0
0.010 1050.4 571.5 3.00 1.59 11.9 -15.7 0.8 2093 32.0 6.0
0.015 1057.6 571.8 2.97 1.56 11.6 -2.5 0.8 2077 31.8 6.0
0.020 1056.0 572.5 2.97 1.57 11.6 -5.9 0.8 2076 31.7 6.0
Plots : Fig. 8.16 U vs Concentration; Fig. 8.18 χU vs Concentration; Fig. 8.20 CE vs Concentration;
Fig. 8.17 κ vs Concentration; Fig. 8.19 πi vs Concentration;
Page 267
267
TABLE 8.19
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE) AND ACOUSTIC IMPEDANCE (Z) AT VARIOUS CONCENTRATIONS
OF IODINE MONOCHLORIDE - PHENOL SYSTEM
Solvent : n-hexane Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 1050.8 567.1 2.96 1.60 11.8 -14.2 0.8 2072 31.9 6.0
0.002 1047.8 567.4 2.96 1.61 11.9 -19.9 0.8 2074 31.9 5.9
0.004 1050.8 568.4 2.97 1.59 11.8 -14.4 0.8 2077 31.9 6.0
0.006 1052.0 567.8 2.97 1.59 11.8 -12.3 0.8 2074 31.9 6.0
0.010 1053.2 568.0 2.97 1.59 11.8 -10.4 0.8 2073 31.9 6.0
0.015 1054.2 568.7 2.96 1.58 11.7 -8.9 0.8 2071 31.8 6.0
0.020 1061.6 569.3 2.98 1.56 11.5 4.7 0.8 2068 31.8 6.0
Plots : Fig. 8.16 U vs Concentration; Fig. 8.18 χU vs Concentration; Fig. 8.20 CE vs Concentration;
Fig. 8.17 κ vs Concentration; Fig. 8.19 πi vs Concentration;
Page 268
268
TABLE 8.20
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE) AND ACOUSTIC IMPEDANCE (Z) AT VARIOUS CONCENTRATIONS
OF IODINE MONOCHLORIDE - CARVACROL SYSTEM
Solvent : n-hexane Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 1049.2 567.0 2.95 1.60 11.8 -17.2 0.8 2069 31.9 5.9
0.002 1048.0 567.2 2.95 1.61 11.9 -19.5 0.8 2072 31.9 5.9
0.004 1047.6 567.6 2.96 1.61 11.9 -20.4 0.8 2074 31.9 5.9
0.006 1057.6 567.9 2.96 1.57 11.6 -1.7 0.8 2067 31.8 6.0
0.010 1054.4 568.4 2.95 1.58 11.6 -8.0 0.8 2064 31.8 6.0
0.015 1053.2 569.1 2.96 1.58 11.7 -10.6 0.8 2068 31.8 6.0
0.020 1056.8 570.0 2.97 1.57 11.6 -4.2 0.8 2068 31.8 6.0
Plots : Fig. 8.16 U vs Concentration; Fig. 8.18 χU vs Concentration; Fig. 8.20 CE vs Concentration;
Fig. 8.17 κ vs Concentration; Fig. 8.19 πi vs Concentration;
Page 269
269
TABLE 8.21
MEAN VALUES OF RELAXATION TIME (ττττ)MEAN VALUES OF GIBB'S FREE ENERGY OF FORMATION (∆G) AND MEAN VALUES OF FORMATION
CONSTANT (K) FOR IODINE MONOCHLORIDE - PHENOLS CHARGE TRANSFER COMPLEXES IN DIFFERENT SOLVENTS AT 303 K
Solvent :- Dichloromethane Chloroform Carbon tetrachloride n-Hexane
ττττ /10-13 ∆G K ττττ /10-13 ∆G K ττττ /10-13 ∆G K ττττ /10-13 ∆G K
DONOR s
kJ mol-1 dm-3 mol-1 s
kJ mol-1 dm-3 mol-1 s
kJ mol-1 dm-3 mol-1 s
kJ mol-1 dm-3 mol-1
o-Cresol 5.4 -12.7 158.8 6.7 -11.0 84.1 9.5 -10.3 60.3 6.3 -9.6 45.6
p-Cresol 5.3 -12.2 125.3 6.8 -10.9 75.5 9.4 -10.0 55.7 6.3 -9.1 39.4
m-Cresol 5.3 -12.1 123.0 6.8 -10.8 73.2 9.5 -10.0 55.3 6.2 -8.6 36.4
Phenol 5.3 -12.0 118.9 6.6 -10.5 65.9 9.4 -9.9 51.9 6.3 -8.8 33.9
Carvacrol 5.3 -11.3 90.3 6.7 -10.3 62.1 9.4 -9.6 49.2 6.3 -7.8 22.1
Page 270
Fig. 8.1 Plots of Ultrasonic velocity vs Concentration
1035
1045
1055
1065
1075
0.000 0.005 0.010 0.015 0.020 0.025
Concentration, M
U,
m s
-1
IC-OCL IC-PCLIC-MCL IC-PLIC-CVL
Solvent : dichloromethane Temperature : 303 K
Fig. 8.2 Plots of Adiabatic compressibility vs Concentration
0.76
0.77
0.78
0.79
0.80
0.81
0.82
0.000 0.005 0.010 0.015 0.020 0.025
Concentration, M
κκ κκ /
10
-9,
kg
-1m
s2
IC-OCL IC-PCLIC-MCL IC-PLIC-CVL
Solvent : dichloromethane Temperature : 303 K
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Fig. 8.3 Plots of Molecular interaction parameter vs Concentration
-30
-20
-10
0
10
20
30
40
0.000 0.005 0.010 0.015 0.020 0.025
Concentration, M
χχ χχU/1
0-3
, m
s-1
IC-OCL IC-PCLIC-MCL IC-PLIC-CVL
Solvent : dichloromethane Temperature : 303 K
Fig. 8.4 Plots of Internal pressure vs Concentration
4340
4360
4380
4400
4420
0.000 0.005 0.010 0.015 0.020 0.025
Concentration, M
ππ ππi, a
tm
IC-OCL IC-PCLIC-MCL IC-PLIC-CVL
Solvent : dichloromethane Temperature : 303 K
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272
Fig. 8.5 Plots of Cohessive energy vs Concentration
32.8
33.0
33.2
33.4
0.000 0.005 0.010 0.015 0.020 0.025
Concentration, M
CE
, kJ m
ol-1
IC-OCL IC-PCL IC-MCLIC-PL IC-CVL
Solvent : dichloromethane Temperature : 303 K
Fig. 8.6 Plots of Ultrasonic velocity vs Concentration
940
950
960
970
980
990
1000
0.000 0.005 0.010 0.015 0.020 0.025
Concentration, M
U,
m s
-1
IC-OCL IC-PCLIC-MCL IC-PLIC-CVL
Solvent : chloroform Temperature : 303 K
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273
Fig. 8.7 Plots of Adiabatic compressibility vs Concentration
0.78
0.80
0.82
0.84
0.86
0.88
0.000 0.005 0.010 0.015 0.020 0.025
Concentration, M
κκ κκ /
10
-9,
kg
-1m
s2
IC-OCL IC-PCLIC-MCL IC-PLIC-CVL
Solvent : chloroform Temperature : 303 K
Fig. 8.8 Plots of Molecular interaction parameter vs Concentration
-50
-30
-10
10
30
50
70
0.000 0.005 0.010 0.015 0.020 0.025
Concentration, M
χχ χχU/1
0-3
, m
s-1
IC-OCL IC-PCLIC-MCL IC-PLIC-CVL
Solvent : chloroform Temperature : 303 K
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274
Fig. 8.9 Plots of Internal pressure vs Concentration
3580
3600
3620
3640
3660
3680
0.000 0.005 0.010 0.015 0.020 0.025
Concentration, M
ππ ππi, a
tm
IC-OCL IC-PCLIC-MCL IC-PLIC-CVL
Solvent : chloroform Temperature : 303 K
Fig. 8.10 Plots of Cohessive energy vs Concentration
33.8
34.0
34.2
34.4
34.6
34.8
0.000 0.005 0.010 0.015 0.020 0.025
Concentration, M
CE
, kJ m
ol-1
IC-OCL IC-PCLIC-MCL IC-PLIC-CVL
Solvent : chloroform Temperature : 303 K
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275
Fig. 8.11 Plots of Ultrasonic velocity vs Concentration
890
900
910
920
930
0.000 0.005 0.010 0.015 0.020 0.025
Concentration, M
U,
m s
-1
IC-OCL IC-PCL IC-MCL IC-PL IC-CVL
Solvent : carbon tetrachloride Temperature : 303 K
Fig. 8.12 Plots of Adiabatic compressibility vs Concentration
0.85
0.86
0.87
0.88
0.89
0.90
0.91
0.92
0.000 0.005 0.010 0.015 0.020 0.025
Concentration, M
κκ κκ /
10
-9,
kg
-1m
s2
IC-OCL
IC-PCL
IC-MCL
IC-PL
IC-CVL
Solvent : carbon tetrachloride Temperature : 303 K
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276
Fig. 8.13 Plots of Molecular interaction parameter vs Concentration
-30
-20
-10
0
10
20
30
40
50
0.000 0.005 0.010 0.015 0.020 0.025
Concentration, M
χχ χχU/1
0-3
, m
s-1
IC-OCL IC-PCL IC-MCLIC-PL IC-CVL
Solvent : carbon tetrachloride Temperature : 303 K
Fig. 8.14 Plots of Internal pressure vs Concentration
3300
3320
3340
3360
3380
3400
0.000 0.005 0.010 0.015 0.020 0.025
Concentration, M
ππ ππi, a
tm
IC-OCL IC-PCL IC-MCLIC-PL IC-CVL
Solvent : carbon tetrachloride Temperature : 303 K
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277
Fig. 8.15 Plots of Cohessive energy vs Concentration
37.6
37.8
38.0
38.2
38.4
38.6
0.000 0.005 0.010 0.015 0.020 0.025
Concentration, M
CE
, kJ m
ol-1
IC-OCL IC-PCLIC-MCL IC-PLIC-CVL
Solvent : carbon tetrachloride Temperature : 303 K
Fig. 8.16 Plots of Ultrasonic velocity vs Concentration
1040
1050
1060
1070
0.000 0.005 0.010 0.015 0.020 0.025
Concentration, M
U,
m s
-1
IC-OCL IC-PCLIC-MCL IC-PLIC-CVL
Solvent : n-hexane Temperature : 303 K
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278
Fig. 8.17 Plots of Adiabatic compressibility vs Concentration
1.54
1.56
1.58
1.60
1.62
0.000 0.005 0.010 0.015 0.020 0.025
Concentration, M
κκ κκ /
10
-9,
kg
-1m
s2
IC-OCL IC-PCL IC-MCL IC-PL IC-CVL
Solvent : n-hexane Temperature : 303 K
Fig. 8.18 Plots of Molecular interaction parameter vs Concentration
-35
-25
-15
-5
5
15
0.000 0.005 0.010 0.015 0.020 0.025
Concentration, M
χχ χχU/1
0-3
, m
s-1
IC-OCL IC-PCLIC-MCL IC-PLIC-CVL
Solvent : n-hexane Temperature : 303 K
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279
Fig. 8.19 Plots of Internal pressure vs Concentration
2060
2075
2090
0.000 0.005 0.010 0.015 0.020 0.025
Concentration, M
ππ ππi, a
tm
IC-OCL IC-PCL IC-MCLIC-PL IC-CVL
Solvent : n-hexane Temperature : 303 K
Fig. 8.20 Plots of Cohessive energy vs Concentration
31.6
31.8
31.9
32.1
0.000 0.005 0.010 0.015 0.020 0.025
Concentration, M
CE
, kJ m
ol-1
IC-OCL IC-PCL IC-MCL IC-PL IC-CVL
Solvent : n-hexane Temperature : 303 K
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CHAPTER – 9
DETERMINATION OF FORMATION CONSTANTS FOR THE CHARGE TRANSFER COMPLEXES OF CERTAIN ETHERS AND IODINE MONOCHLORIDE IN DIFFERENT SOLVENTS
9.1. INTRODUCTION
Aryl ethers undergo electrophilic substitution reaction with halogens.
The reaction mechanism involves the formation of charge transfer complex
between aryl ether and halogen1-5. The formation of charge transfer complex
has been established by spectrophotometric methods, and the stability
constant values have been reported6-8. It may be pointed out that aryl ethers
and heterocyclic aromatic compounds can function as π- and n-electron
donors, since ethereal oxygen in aryl ethers, and heteroatom in heterocyclic
aromatic compounds contain lone pair of electrons. It has been found that
aliphatic and aromatic ethers form charge transfer complexes with acceptors
like iodine, iodine monochloride and tetrachloroethylene9-11.
Ultrasonic velocity measurements can be used to detect charge transfer
(CT) complexes in solution. Bhat and coworkers12 proposed an equation to
calculate the formation constants of complexes in binary mixtures at
moderate concentration. However, this method can be used only for relatively
strong donor-acceptor complexes. Recently, Kannappan et al modified Bhatt’s
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equation and deduced another equation based on the assumption that the
deviation from ideal behaviour may be due to complex formation. This method
has been successfully used by several workers13-16 to calculate the formation
constants of complexes in solution.
This chapter deals with solvent and structural effects on the stability of
CT complexes formed between iodine monochloride (acceptor) and ethers
(donors) and identification of molecular property which is primarily
responsible for complex formation. The following four ethers were used as
donors in the present investigation:
Diphenyl ether, 4-chloroanisole, anisole and 1,4-dioxane.
The structures of ethers used as donors are given below:
O CH3
OCl
diphenyl ether 4-chloroanisole
CH3
O
O
O
anisole 1,4-dioxane
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283
The four solvents (medium) used in this investigation are:
Dichloromethane, chloroform, carbon tetrachloride and n-hexane.
These solvents are less polar and have low dielectric constants. It may be
pointed out that CT complexes are stable only in less polar solvents. The
formation constants are determined for the above sixteen systems at 303 K.
9.2. RESULTS AND DISCUSSION
The measured values of ultrasonic velocity, density, viscosity and
computed values of adiabatic compressibility, absorption coefficient,
molecular interaction parameter, free length, internal pressure, cohesive
energy, acoustic impedance, Lenard Jones Potential, relaxation time, free
energy of formation, free energy of activation and formation constants for
charge transfer complexes of iodine monochloride and four ethers in four
different solvents at 303 K are presented in Tables 9.1 – 9.17.
9.2.1. Ultrasonic Velocity (U)
The plots of ultrasonic velocity vs concentration are given in Fig. 9.1 for
the four systems in dichloromethane, while Fig. 9.6 contains similar plots for
chloroform solvent at 303 K. In these eight systems, the ultrasonic velocity
uniformly decreases with increase in concentration suggesting negative
deviation form ideal behaviour. The curves are steeper in systems containing
diphenyl ether, anisole and 1,4-dioxane as donors. These ethers may form
strong complexes with iodine monochloride as compared to 4-chloroanisole.
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284
Plots of ultrasonic velocity vs concentration for the four systems in carbon
tetrachloride are given in Fig. 9.11 while similar plots for n-hexane solvent
are given in Fig. 9.16. The variation of ultrasonic velocity with concentration
in these two solvents is interesting to note. In carbon tetrachloride medium,
the ultrasonic velocity increases with increase in concentration in systems
containing anisole as donor. But the ultrasonic velocity decreases with
increase in concentration in systems in which 4-chloroanisole and diphenyl
ether are donors. Further, in 1,4-dioxane system, the ultrasonic velocity
decreases with increase in concentration, reaches a minimum at a particular
concentration and then increases. These observations also suggest that there
is deviation from ideal behaviour in the case of the four systems in carbon
tetrachloride solution. In n-hexane medium, the decrease in ultrasonic
velocity is observed in systems containing diphenyl ether and 1,4-dioxane
while increase in velocity is observed in systems in which anisole and
4-chloroanisole are used as donors. Thus, in the sixteen systems the
ultrasonic velocity depends upon the concentration and structure of donor.
9.2.2. Adiabatic Compressibility (κκκκ)
The adiabatic compressibility values for various compositions of four
systems in each solvent have been calculated from the measured values of
ultrasonic velocities and densities. In the case of dichloromethane and
chloroform solvents, the adiabatic compressibility decreases with increase in
concentration for all the ethers as shown in the Figs. 9.2 and 9.7. This
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indicates that there is considerable formation of donor-acceptor complexes for
all the ethers in these two solvents. In the case of carbon tetrachloride, there
is a decrease in adiabatic compressibility with increase in concentration for
diphenyl ether and 4-chloroanisole which is quite reverse in the case of the
other two as shown in Fig. 9.12. In the case of n-hexane medium, the
decreasing trend is observed for diphenyl ether and 1,4-dioxane, indicating
the formation of charge transfer complexes at higher concentration. But the
trend is quite opposite in the case of 4-chloroanisole and anisole as indicated
in Fig. 9.17.
9.2.3. Absorption Coefficient (α/α/α/α/f2)
The absorption coefficient depends on the type of molecular species and
it is a measure of intermolecular attraction. In all these systems, there is
strong attraction between the electrophile iodine monochloride and ethers
which act as electron donors. It is found that in a given medium, the
absorption coefficient values are almost constant for all the ethers, indicating
that it is intrinsic property of the CT complex. However, these values are
different for different systems.
9.2.4. Molecular Interaction Parameter (χχχχU)
The molecular interaction parameter is indicative of the extent of
deviation from ideal behaviour which may be due to the formation of charge
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transfer complex. It can be used to assess the strength of molecular
attraction between the donor and acceptor in solution. Both positive and
negative values are obtained for all these systems in all the four media. This
suggests that some systems exhibit a positive deviation while others show a
negative deviation from ideal behaviour. These observations establish that in
all the systems, charge transfer complexes are formed. Plots of molecular
interaction parameter vs concentration are given in Figs. 9.3, 9.8, 9.13
and 9.18.
9.2.5. Relaxation Time (ττττ) and Free Length (Lf)
The relaxation time can be calculated from coefficient of viscosity,
density and ultrasonic velocity of the mixtures. The mean values of relaxation
time for each system are given in Table 9.17. It is found that the relaxation
time value is a constant for a particular system in a given solvent. This
indicates that there is formation of CT complex in all the systems and similar
complexes are formed.
The free length values are also found to be constant for all the systems
in a medium. It is found that these values do not vary much when the
solvents are different. It may be noted that the free length values are different
from those of pure components and this also establishes the formation of CT
complexes between iodine monochloride and ethers.
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9.2.6. Internal Pressure
The internal pressure (πi) in binary mixtures is a measure of
intermolecular attraction between molecules of the components. The plots of
internal pressure vs concentration for all the four systems in
dichloromethane are shown in Fig. 9.4. The internal pressure increases first
and then decreases with increase in concentration for
4-chloroanisole and 1,4-dioxane. It is quite opposite in the case of diphenyl
ether and anisole. The same trend is almost seen in the case of chloroform
medium also. The plots of internal pressure vs concentration are given in Fig.
9.9. In the case of carbon tetrachloride and n-hexane, the internal pressure
values are found to be almost constant, and there is only a slight variation in
internal pressure, for all the systems. Figures 9.14 and 9.19 contain the plots
of internal pressure vs concentration in carbon tetrachloride and n-hexane
media respectively. There is one common observation in all the systems.
Whether the internal pressure value increases or decreases with increase in
concentration, the internal pressure is the highest at a particular
concentration which is characteristic of the system. This indicates that the
extent of complexation depends upon the structure of donor, the medium and
also the concentration.
9.2.7. Cohesive Energy (CE)
The cohesive energy in a liquid mixture is a measure of potential energy
of attraction between the molecules of the components. The interaction
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between the molecules in a system can be assessed from cohesive energy
values. Plots of cohesive energy vs concentration for all the four ethers in
dichloromethane are given in Fig.9.5. It has been observed that cohesive
energy increases initially and then decreases in the case of 4-chloroanisole
and 1,4-dioxane but in the case of diphenyl ether and anisole it decreases
and then increases with increase in concentration. It is seen in general, that
the cohesive energy value is high at a particular concentration in each
system. This is similar to the variation in internal pressure value with
concentration. Thus, the extent of complexation is concentration dependent.
Plots of cohesive energy vs concentration are given in Figs. 9.10, 9.15 and
9.20.
9.2.8. Acoustic Impedance (Z)
The acoustic impedance for all the systems in a particular solvent is
found to be constant. Thus, acoustic impedance values vary with change in
medium, which may be due to difference in the stability of the CT complexes
in different media.
9.2.9. Lenard Jones Potential (LJP)
The Lenard Jones Potential values are computed for all the systems in
all the four solvents. The Lenard Jones Potential is found to be almost a
constant for all the ethers in a particular solvent. But the value increases
with change in solvent in the following order: n-hexane > dichloromethane >
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chloroform > carbon tetrachloride. Since Lenard Jones Potential is a measure
of repulsive forces, which suggests that the repulsive forces operate
significantly in solvents of higher dielectric constant.
9.2.10. Free Energy of Formation (∆G)
The free energy of formation can be calculated from the formation
constant value. The free energy of formation values are determined for all the
sixteen systems (Table 9.17). The negative values of free energy of formation
for all the systems in all the solvents suggest that the donor-acceptor
complexes formed in all these systems are thermodynamically stable. The
values of free energy of formation in different solvents indicate that the
stability depends upon the solvent which is in the following order:
Dichloromethane > chloroform > carbon tetrachloride > n-hexane.
9.2.11. Free Energy of Activation (∆G#) and Relaxation Time (ττττ)
The constant values of free energy of activation and relaxation time for
all the systems in each solvent indicate the formation of similar type of
complexes.
9.2.12. Formation Constant (K)
The formation constants of CT complexes for various ethers and iodine
monochloride in different solvents are calculated and tabulated (Fig.9.17). It
may be noted that the formation constant values are almost constant for a
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given system at a given temperature, indicating that the formation constant
depends on the structure of ethers. By comparing the values of formation
constants of four ethers in each solvent, the ease of complexation with iodine
monochloride and ethers is found to be in the order:
Diphenyl ether > 4-chloroanisole > anisole > 1,4-dioxane.
During the complexation between ether and iodine monochloride, ethereal
oxygen donates electron which is attracted by positive end of dipole in iodine
monochloride. The diphenyl ether contains electron releasing phenyl groups
on either side of the donor. Therefore, it forms relatively more stable complex
with iodine monochloride. In 4-chloroanisole, chlorine in the para position to
methoxy group releases electron by mesomeric effect although it withdraws
electrons by -I effect. But mesomeric effect is stronger than inductive effect.
However, in anisole molecule, the resonance effect is limited although
methoxy group is directly attached to a phenyl ring. In 1,4-dioxane molecule,
no mesomeric effect is possible and hence, the stability constant value is the
least in this case.
9.3. Correlation of stability constants with molecular properties
The complex formation is influenced by the molecular properties such
as polarizability (α), dipole moment (µ) and dielectric constant (ε) of donor
molecules17,18. These parameters for the four ethers are listed in Table 9.18.
The formation constant increases with increase in polarizability of donor
molecules. Therefore, increase in polarizability of donor increases the ease of
complexation. Further, formation constant increases with increase in dipole
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moment of donor in three systems. However, in the case of diphenyl ether, the
formation constant is abnormally high even though it has a low dipole
moment. This may be due to rich π-electrons in diphenyl ether. It is also
found that the stability constant increases with increase in dielectric constant
of donor molecules except diphenyl ether. The greater stability constant of
diphenyl ether may be due to increase in π electron density in the two
neighbouring phenyl rings. These correlations of formation constant with
molecular properties indicate that, it is the polarizability factor, which
predominantly determines the ease of complexation. Thus, the acceptor
molecule first polarizes the donor molecule during the formation of a charge
transfer complex. The stability of charge transfer complex is also affected by
the polarity of the medium. As the dielectric constant of the medium
increases, the stability constant of the charge transfer complex also
increases.
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292
REFERENCES
1. De la Mare, P.B.D.and Ridd, J.H., Aromatic Substitution: Nitration and Halogenation,
Baterworth’s Scientific Publications, London, 1959.
2. Stock, L.M. and Brown, H.C., Advan. Phys. Org. Chem., 1, 1963, 35.
3. Berliner, E., Prog. Phys. Org. Chem., 2, 1964, 253.
4. Norman, R.O.C.and Taylor, R., Electrophilic substitutions in Benzenoid Compounds,
American Elsevier Publishing Co., New York, 1965.
5. Marino, G., Tetrahedron, 21, 1965, 843.
6. Dewar, M.J.S., Kubba, V.P. and Petit, R., J. Chem. Soc., 1958, 3073.
7. Abraham, R.J., Sheppard, R.C., Thomas, W.A. and Turner, S., Chem. Common.,
1965, 43.
8. Winn, M. and Bordwell, F.G., J. Org. Chem., 32, 1967, 1810.
9. Mahendran, S., Ph.D. Thesis, University of Madras, 2002.
10. Kothai, S., Ph.D. Thesis, University of Madras, 2003.
11. Indra Gandhi, N., Ph.D. Thesis, University of Madras, 2006.
12. Marwein, B.L. and Bhat, S.N., Acustica, 58, 1985, 243.
13. Kannappan, V. and Jaya Santhi, R., J. Acous. Soc. Ind., 29, 2001, 192.
14. Kannappan, V. and Kothai, S., J. Acous. Soc. Ind., 30, 2002, 76.
15. Kannappan, V., Jaya Santhi, R. and Malar, E.J.P., Phys. Chem. Liq., 40, 2002, 507.
16. Kannappan, V. and Jaya Santhi, R. and Xavier Jesu Raja,S., Phys. Chem. Liq., 14(2),
2003, 133.
17. Timmernian, J., Physico-chemical constants fo pure organic compounds, Elsevier,
Regensburg, Germany, 1950.
18. McClellan, A.L., Tables of experimental dipole moments, W.H. Freeman & Company,
San Francisco and London, 1963.
Page 293
TABLE 9.1
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE), ACOUSTIC IMPEDANCE (Z) AND LENARD JONES POTENTIAL (LJP) AT VARIOUS
CONCENTRATIONS OF IODINE MONOCHLORIDE - DIPHENYL ETHER SYSTEM
Solvent : dichloromethane Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105 LJP
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 1052.0 1261.4 5.61 0.72 10.0 -2.4 0.5 4944 33.7 13.3 4.5
0.002 1050.0 1258.1 5.59 0.72 10.1 -6.2 0.5 4931 33.7 13.2 4.5
0.003 1049.6 1259.2 5.60 0.72 10.1 -7.1 0.5 4937 33.8 13.2 4.4
0.004 1049.0 1257.6 5.59 0.72 10.1 -8.3 0.5 4928 33.7 13.2 4.4
0.005 1048.6 1256.8 5.55 0.72 10.1 -9.1 0.5 4909 33.6 13.2 4.4
0.006 1048.0 1261.0 5.63 0.72 10.2 -10.3 0.5 4952 33.8 13.2 4.4
0.007 1047.2 1258.9 5.60 0.72 10.2 -11.9 0.5 4935 33.8 13.2 4.4
0.008 1046.4 1260.3 5.61 0.72 10.2 -13.5 0.5 4943 33.8 13.2 4.3
0.009 1046.0 1258.1 5.65 0.73 10.3 -14.4 0.5 4956 34.0 13.2 4.3
0.010 1045.2 1259.7 5.61 0.73 10.2 -16.0 0.5 4940 33.8 13.2 4.3
Plots : Fig. 9.1 U vs Concentration; Fig. 9.3 χU vs Concentration; Fig. 9.5 CE vs Concentration;
Fig. 9.2 κ vs Concentration; Fig. 9.4 πi vs Concentration;
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294
TABLE 9.2
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE), ACOUSTIC IMPEDANCE (Z) AND LENARD JONES POTENTIAL (LJP) AT VARIOUS
CONCENTRATIONS OF IODINE MONOCHLORIDE - 4-CHLOROANISOLE SYSTEM
Solvent : dichloromethane Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105 LJP
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 1054.8 1261.4 5.70 0.71 10.1 3.0 0.5 4978 34.0 13.3 4.6
0.002 1054.4 1262.9 5.60 0.71 9.9 2.2 0.5 4936 33.6 13.3 4.6
0.003 1054.0 1262.6 5.67 0.71 10.1 1.4 0.5 4964 33.8 13.3 4.6
0.004 1053.2 1261.1 5.64 0.71 10.1 -0.2 0.5 4950 33.8 13.3 4.6
0.005 1052.8 1262.6 5.67 0.71 10.1 -1.0 0.5 4964 33.9 13.3 4.5
0.006 1052.0 1263.2 5.68 0.72 10.2 -2.6 0.5 4974 33.9 13.3 4.5
0.007 1051.6 1264.1 5.69 0.72 10.2 -3.4 0.5 4980 33.9 13.3 4.5
0.008 1050.8 1264.7 5.68 0.72 10.2 -5.0 0.5 4976 33.9 13.3 4.5
0.009 1050.4 1263.8 5.66 0.72 10.2 -5.8 0.5 4966 33.9 13.3 4.5
0.010 1049.6 1265.3 5.62 0.72 10.1 -7.4 0.5 4955 33.8 13.3 4.4
Plots : Fig. 9.1 U vs Concentration; Fig. 9.3 χU vs Concentration; Fig. 9.5 CE vs Concentration;
Fig. 9.2 κ vs Concentration; Fig. 9.4 πi vs Concentration;
Page 295
295
TABLE 9.3
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE), ACOUSTIC IMPEDANCE (Z) AND LENARD JONES POTENTIAL (LJP) AT VARIOUS
CONCENTRATIONS OF IODINE MONOCHLORIDE - ANISOLE SYSTEM
Solvent : dichloromethane Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105 LJP
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 1052.8 1256.6 5.61 0.72 10.1 -0.8 0.5 4931 33.8 13.2 4.5
0.002 1050.8 1257.9 5.62 0.72 10.1 -4.7 0.5 4941 33.8 13.2 4.5
0.003 1050.6 1257.8 5.61 0.72 10.1 -5.1 0.5 4937 33.8 13.2 4.5
0.004 1048.8 1256.7 5.58 0.72 10.1 -8.6 0.5 4925 33.7 13.2 4.4
0.005 1048.0 1258.6 5.59 0.72 10.1 -10.2 0.5 4933 33.7 13.2 4.4
0.006 1047.4 1259.1 5.58 0.72 10.1 -11.4 0.5 4929 33.7 13.2 4.4
0.007 1047.2 1257.7 5.43 0.73 9.9 -11.8 0.5 4862 33.3 13.2 4.4
0.008 1047.0 1258.5 5.56 0.72 10.1 -12.2 0.5 4919 33.7 13.2 4.4
0.009 1046.6 1256.9 5.54 0.73 10.1 -13.1 0.5 4908 33.6 13.2 4.3
0.010 1044.8 1258.4 5.57 0.73 10.2 -16.5 0.5 4926 33.7 13.1 4.3
Plots : Fig. 9.1 U vs Concentration; Fig. 9.3 χU vs Concentration; Fig. 9.5 CE vs Concentration;
Fig. 9.2 κ vs Concentration; Fig. 9.4 πi vs Concentration;
Page 296
296
TABLE 9.4
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE), ACOUSTIC IMPEDANCE (Z) AND LENARD JONES POTENTIAL (LJP) AT VARIOUS
CONCENTRATIONS OF IODINE MONOCHLORIDE - 1,4 DIOXANE SYSTEM
Solvent : dichloromethane Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105 LJP
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 1052.9 1257.1 5.61 0.72 10.0 -0.6 0.5 4930 33.7 13.2 4.5
0.002 1051.8 1258.2 5.67 0.72 10.2 -2.8 0.5 4960 33.9 13.2 4.5
0.003 1052.4 1258.1 5.66 0.72 10.2 -1.7 0.5 4956 33.9 13.2 4.5
0.004 1050.2 1258.0 5.66 0.72 10.2 -5.9 0.5 4961 33.9 13.2 4.5
0.005 1048.0 1257.5 5.68 0.72 10.3 -10.1 0.5 4972 34.0 13.2 4.4
0.006 1048.2 1260.6 5.71 0.72 10.3 -9.8 0.5 4992 34.1 13.2 4.4
0.007 1046.6 1261.0 5.66 0.72 10.3 -12.8 0.5 4971 33.9 13.2 4.3
0.008 1046.0 1259.0 5.64 0.73 10.3 -14.0 0.5 4961 33.9 13.2 4.3
0.009 1045.6 1257.8 5.65 0.73 10.3 -14.8 0.5 4961 34.0 13.2 4.3
0.010 1045.2 1258.2 5.64 0.73 10.3 -15.6 0.5 4960 34.0 13.2 4.3
Plots : Fig. 9.1 U vs Concentration; Fig. 9.3 χU vs Concentration; Fig. 9.5 CE vs Concentration;
Fig. 9.2 κ vs Concentration; Fig. 9.4 πi vs Concentration;
Page 297
297
TABLE 9.5
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE), ACOUSTIC IMPEDANCE (Z) AND LENARD JONES POTENTIAL (LJP) AT VARIOUS
CONCENTRATIONS OF IODINE MONOCHLORIDE - DIPHENYL ETHER SYSTEM
Solvent : chloroform
Temperature : 303K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105 LJP
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 964.8 1411.2 6.70 0.76 13.9 -3.0 0.5 4088 35.0 13.6 2.1
0.002 964.4 1410.8 6.75 0.76 14.0 -4.0 0.5 4101 35.2 13.6 2.1
0.003 964.0 1412.2 6.72 0.76 14.0 -5.0 0.5 4096 35.1 13.6 2.1
0.004 963.9 1410.6 6.70 0.76 13.9 -5.3 0.5 4085 35.0 13.6 2.1
0.005 963.6 1411.8 6.71 0.76 14.0 -6.1 0.5 4093 35.1 13.6 2.1
0.006 962.8 1412.2 6.73 0.76 14.0 -7.8 0.5 4101 35.1 13.6 2.1
0.007 962.4 1413.5 6.78 0.76 14.2 -8.8 0.5 4119 35.3 13.6 2.1
0.008 961.6 1412.5 6.74 0.77 14.1 -10.6 0.5 4104 35.2 13.6 2.0
0.009 960.8 1413.2 6.73 0.77 14.1 -12.4 0.5 4104 35.1 13.6 2.0
0.010 960.0 1413.1 6.80 0.77 14.3 -14.1 0.5 4126 35.3 13.6 2.0
Plots : Fig. 9.6 U vs Concentration; Fig. 9.8 χU vs Concentration; Fig. 9.10 CE vs Concentration;
Fig. 9.7 κ vs Concentration; Fig. 9.9 πi vs Concentration;
Page 298
298
TABLE 9.6
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE), ACOUSTIC IMPEDANCE (Z) AND LENARD JONES POTENTIAL (LJP) AT VARIOUS
CONCENTRATIONS OF IODINE MONOCHLORIDE - 4-CHLOROANISOLE SYSTEM
Solvent : chloroform
Temperature : 303K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105 LJP
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 966.4 1411.7 6.71 0.76 13.9 0.3 0.5 4088 35.0 13.6 2.2
0.002 966.0 1412.8 6.72 0.76 13.9 -0.6 0.5 4094 35.1 13.6 2.1
0.003 965.2 1412.4 6.73 0.76 13.9 -2.4 0.5 4098 35.1 13.6 2.1
0.004 964.8 1413.2 6.77 0.76 14.0 -3.3 0.5 4111 35.2 13.6 2.1
0.005 964.4 1413.5 6.77 0.76 14.0 -4.2 0.5 4113 35.2 13.6 2.1
0.006 964.0 1412.4 6.73 0.76 14.0 -5.2 0.5 4097 35.1 13.6 2.1
0.007 963.2 1412.1 6.70 0.76 14.0 -6.9 0.5 4090 35.0 13.6 2.1
0.008 962.4 1412.6 6.73 0.76 14.1 -8.7 0.5 4103 35.1 13.6 2.1
0.009 962.0 1411.8 6.73 0.77 14.1 -9.6 0.5 4101 35.2 13.6 2.0
0.010 961.6 1412.2 6.73 0.77 14.1 -10.5 0.5 4101 35.1 13.6 2.0
Plots : Fig. 9.6 U vs Concentration; Fig. 9.8 χU vs Concentration; Fig. 9.10 CE vs Concentration;
Fig. 9.7 κ vs Concentration; Fig. 9.9 πi vs Concentration;
Page 299
299
TABLE 9.7
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE), ACOUSTIC IMPEDANCE (Z) AND LENARD JONES POTENTIAL (LJP) AT VARIOUS
CONCENTRATIONS OF IODINE MONOCHLORIDE - ANISOLE SYSTEM
Solvent : chloroform
Temperature : 303K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105 LJP
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 967.6 1412.1 6.64 0.76 13.6 2.8 0.5 4064 34.8 13.7 2.2
0.002 966.8 1414.3 6.72 0.76 13.8 1.0 0.5 4095 35.0 13.7 2.2
0.003 966.4 1412.2 6.75 0.76 13.9 0.1 0.5 4101 35.1 13.6 2.2
0.004 965.2 1413.0 6.70 0.76 13.9 -2.5 0.5 4089 35.0 13.6 2.1
0.005 964.8 1412.9 6.67 0.76 13.8 -3.5 0.5 4079 34.9 13.6 2.1
0.006 964.0 1412.8 6.72 0.76 14.0 -5.2 0.5 4098 35.1 13.6 2.1
0.007 963.2 1413.0 6.72 0.76 14.0 -7.0 0.5 4098 35.1 13.6 2.1
0.008 962.4 1413.7 6.73 0.76 14.0 -8.8 0.5 4105 35.1 13.6 2.1
0.009 962.0 1414.1 6.67 0.76 13.9 -9.7 0.5 4089 35.0 13.6 2.0
0.010 961.2 1414.0 6.72 0.77 14.1 -11.5 0.5 4103 35.1 13.6 2.0
Plots : Fig. 9.6 U vs Concentration; Fig. 9.8 χU vs Concentration; Fig. 9.10 CE vs Concentration;
Fig. 9.7 κ vs Concentration; Fig. 9.9 πi vs Concentration;
Page 300
300
TABLE 9.8
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE), ACOUSTIC IMPEDANCE (Z) AND LENARD JONES POTENTIAL (LJP) AT VARIOUS
CONCENTRATIONS OF IODINE MONOCHLORIDE - 1,4-DIOXANE SYSTEM Solvent : chloroform
Temperature : 303K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105 LJP
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 967.6 1411.3 6.75 0.76 13.9 2.8 0.5 4098 35.1 13.7 2.2
0.002 966.0 1411.2 6.75 0.76 13.9 -0.6 0.5 4099 35.1 13.6 2.1
0.003 965.6 1410.6 6.73 0.76 13.9 -1.5 0.5 4093 35.1 13.6 2.1
0.004 965.2 1412.8 6.80 0.76 14.1 -2.5 0.5 4119 35.3 13.6 2.1
0.005 964.0 1411.4 6.82 0.76 14.2 -5.0 0.5 4125 35.3 13.6 2.1
0.006 963.6 1411.6 6.81 0.76 14.2 -6.0 0.5 4124 35.3 13.6 2.1
0.007 962.4 1410.9 6.78 0.77 14.2 -8.5 0.5 4115 35.3 13.6 2.1
0.008 961.6 1410.8 6.80 0.77 14.3 -10.3 0.5 4123 35.3 13.6 2.0
0.009 960.8 1410.8 6.77 0.77 14.2 -12.0 0.5 4116 35.3 13.6 2.0
0.010 960.4 1411.9 6.75 0.77 14.2 -12.9 0.5 4113 35.2 13.6 2.0
Plots : Fig. 9.6 U vs Concentration; Fig. 9.8 χU vs Concentration; Fig. 9.10 CE vs Concentration;
Fig. 9.7 κ vs Concentration; Fig. 9.9 πi vs Concentration;
Page 301
301
TABLE 9.9
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE), ACOUSTIC IMPEDANCE (Z) AND LENARD JONES POTENTIAL (LJP) AT VARIOUS
CONCENTRATIONS OF IODINE MONOCHLORIDE - DIPHENYL ETHER SYSTEM
Solvent : carbon tetrachloride
Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105 LJP
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 908.8 1515.0 8.78 0.80 20.3 6.5 0.6 3759 38.7 13.8 0.9
0.002 908.0 1514.2 8.81 0.80 20.4 4.5 0.6 3768 38.8 13.7 0.9
0.003 907.2 1513.5 8.79 0.80 20.5 2.5 0.6 3763 38.7 13.7 0.9
0.004 907.2 1514.4 8.83 0.80 20.5 2.4 0.6 3773 38.8 13.7 0.9
0.005 906.4 1513.2 8.80 0.80 20.5 0.4 0.6 3767 38.8 13.7 0.8
0.006 905.6 1514.6 8.83 0.81 20.6 -1.5 0.6 3776 38.9 13.7 0.8
0.007 904.8 1514.2 8.84 0.81 20.7 -3.5 0.6 3779 38.9 13.7 0.8
0.008 904.4 1514.2 8.86 0.81 20.8 -4.5 0.6 3784 38.9 13.7 0.8
0.009 904.0 1514.9 8.79 0.81 20.6 -5.6 0.6 3770 38.8 13.7 0.8
0.010 903.2 1515.1 8.84 0.81 20.8 -7.5 0.6 3784 38.9 13.7 0.8
Plots : Fig. 9.11 U vs Concentration; Fig. 9.13 χU vs Concentration; Fig. 9.15 CE vs Concentration;
Fig. 9.12 κ vs Concentration; Fig. 9.14 πi vs Concentration;
Page 302
302
TABLE 9.10
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE), ACOUSTIC IMPEDANCE (Z) AND LENARD JONES POTENTIAL (LJP) AT VARIOUS
CONCENTRATIONS OF IODINE MONOCHLORIDE - 4-CHLOROANISOLE SYSTEM
Solvent : carbon tetrachloride
Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105 LJP
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 906.8 1516.7 8.91 0.80 20.7 2.1 0.6 3795 39.0 13.8 0.8
0.002 906.4 1516.9 8.85 0.80 20.6 1.0 0.6 3783 38.9 13.7 0.8
0.003 906.2 1517.7 8.89 0.80 20.7 0.4 0.6 3794 38.9 13.8 0.8
0.004 905.6 1516.2 8.90 0.80 20.8 -1.0 0.6 3794 39.0 13.7 0.8
0.005 905.2 1515.9 8.94 0.81 20.9 -2.1 0.6 3803 39.1 13.7 0.8
0.006 904.0 1515.8 8.84 0.81 20.8 -4.8 0.6 3785 38.9 13.7 0.8
0.007 903.2 1516.7 8.87 0.81 20.9 -6.8 0.6 3794 39.0 13.7 0.8
0.008 902.4 1518.2 8.90 0.81 21.0 -8.7 0.6 3804 39.0 13.7 0.8
0.009 901.6 1516.0 8.92 0.81 21.1 -10.6 0.6 3806 39.1 13.7 0.7
0.010 900.8 1517.3 8.95 0.81 21.2 -12.5 0.6 3817 39.2 13.7 0.7
Plots : Fig. 9.11 U vs Concentration; Fig. 9.13 χU vs Concentration; Fig. 9.15 CE vs Concentration;
Fig. 9.12 κ vs Concentration; Fig. 9.14 πi vs Concentration;
Page 303
303
TABLE 9.11
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE), ACOUSTIC IMPEDANCE (Z) AND LENARD JONES POTENTIAL (LJP) AT VARIOUS
CONCENTRATIONS OF IODINE MONOCHLORIDE - ANISOLE SYSTEM
Solvent : carbon tetrachloride
Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105 LJP
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 899.6 1513.0 8.73 0.82 20.8 -13.8 0.6 3765 38.8 13.6 0.7
0.002 900.4 1513.4 8.69 0.82 20.7 -12.2 0.6 3756 38.7 13.6 0.7
0.003 901.2 1513.5 8.74 0.81 20.7 -10.6 0.6 3764 38.8 13.6 0.7
0.004 902.0 1514.0 8.72 0.81 20.6 -9.0 0.6 3761 38.7 13.7 0.8
0.005 902.4 1514.4 8.77 0.81 20.7 -8.3 0.6 3772 38.8 13.7 0.8
0.006 903.4 1513.8 8.81 0.81 20.8 -6.2 0.6 3777 38.9 13.7 0.8
0.007 903.6 1514.0 8.76 0.81 20.6 -6.0 0.6 3766 38.8 13.7 0.8
0.008 904.0 1512.5 8.75 0.81 20.6 -5.2 0.6 3760 38.7 13.7 0.8
0.009 904.4 1513.4 8.69 0.81 20.4 -4.5 0.6 3749 38.6 13.7 0.8
0.010 905.0 1512.5 8.72 0.81 20.5 -3.3 0.6 3753 38.6 13.7 0.8
Plots : Fig. 9.11 U vs Concentration; Fig. 9.13 χU vs Concentration; Fig. 9.15 CE vs Concentration;
Fig. 9.12 κ vs Concentration; Fig. 9.14 πi vs Concentration;
Page 304
304
TABLE 9.12
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE), ACOUSTIC IMPEDANCE (Z) AND LENARD JONES POTENTIAL (LJP) AT VARIOUS
CONCENTRATIONS OF IODINE MONOCHLORIDE - 1,4-DIOXANE SYSTEM
Solvent : carbon tetrachloride
Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105 LJP
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 907.6 1522.1 9.05 0.80 20.9 3.8 0.6 3833 39.2 13.8 0.9
0.002 907.2 1522.1 9.03 0.80 20.9 2.8 0.6 3828 39.2 13.8 0.9
0.003 906.8 1521.2 9.00 0.80 20.9 1.8 0.6 3823 39.2 13.8 0.8
0.004 905.6 1521.7 9.02 0.80 21.0 -1.0 0.6 3830 39.2 13.8 0.8
0.005 906.0 1521.5 8.99 0.80 20.9 -0.3 0.6 3822 39.1 13.8 0.8
0.006 907.6 1522.3 9.03 0.80 20.9 3.1 0.6 3830 39.2 13.8 0.9
0.007 909.6 1521.2 9.02 0.79 20.7 7.4 0.6 3821 39.1 13.8 0.9
0.008 912.0 1522.2 9.02 0.79 20.5 12.6 0.6 3818 39.1 13.9 1.0
0.009 912.4 1521.4 9.02 0.79 20.5 13.3 0.6 3816 39.1 13.9 1.0
0.010 912.8 1522.3 9.03 0.79 20.5 14.1 0.6 3819 39.1 13.9 1.0
Plots : Fig. 9.11 U vs Concentration; Fig. 9.13 χU vs Concentration; Fig. 9.15 CE vs Concentration;
Fig. 9.12 κ vs Concentration; Fig. 9.14 πi vs Concentration;
Page 305
305
TABLE 9.13
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE), ACOUSTIC IMPEDANCE (Z) AND LENARD JONES POTENTIAL (LJP) AT VARIOUS
CONCENTRATIONS OF IODINE MONOCHLORIDE - DIPHENYL ETHER SYSTEM
Solvent : n-hexane
Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105 LJP
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 1052.8 625.2 3.27 1.44 11.8 -10.4 0.8 2322 32.4 6.6 4.5
0.002 1051.6 625.4 3.28 1.45 11.9 -12.8 0.8 2328 32.5 6.6 4.5
0.003 1050.4 626.0 3.26 1.45 11.8 -15.1 0.8 2322 32.4 6.6 4.5
0.004 1049.2 626.3 3.27 1.45 11.9 -17.4 0.8 2327 32.5 6.6 4.4
0.005 1048.0 625.8 3.26 1.45 11.9 -19.8 0.8 2322 32.4 6.6 4.4
0.006 1047.8 627.0 3.27 1.45 11.9 -20.2 0.8 2329 32.5 6.6 4.4
0.007 1047.6 626.6 3.26 1.45 11.9 -20.7 0.8 2324 32.4 6.6 4.4
0.008 1047.2 626.8 3.26 1.45 11.9 -21.5 0.8 2323 32.4 6.6 4.4
0.009 1046.8 626.8 3.26 1.46 11.9 -22.3 0.8 2325 32.5 6.6 4.4
0.010 1046.4 627.2 3.27 1.46 12.0 -23.1 0.8 2329 32.5 6.6 4.3
Plots : Fig. 9.16 U vs Concentration; Fig. 9.18 χU vs Concentration; Fig. 9.20 CE vs Concentration;
Fig. 9.17 κ vs Concentration; Fig. 9.19 πi vs Concentration;
Page 306
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TABLE 9.14
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE), ACOUSTIC IMPEDANCE (Z) AND LENARD JONES POTENTIAL (LJP) AT VARIOUS
CONCENTRATIONS OF IODINE MONOCHLORIDE - 4-CHLOROANISOLE SYSTEM
Solvent : n-hexane
Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105 LJP
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 1050.8 631.2 3.34 1.43 12.0 -14.2 0.8 2365 32.7 6.6 4.5
0.002 1051.6 631.9 3.33 1.43 11.9 -12.7 0.8 2360 32.6 6.6 4.5
0.003 1053.2 632.0 3.34 1.43 11.9 -9.8 0.7 2361 32.6 6.7 4.6
0.004 1054.0 632.4 3.33 1.42 11.8 -8.3 0.7 2358 32.6 6.7 4.6
0.005 1054.4 632.5 3.33 1.42 11.8 -7.6 0.7 2358 32.6 6.7 4.6
0.006 1055.6 632.7 3.34 1.42 11.8 -5.4 0.7 2362 32.6 6.7 4.6
0.007 1056.0 632.7 3.36 1.42 11.8 -4.7 0.7 2364 32.7 6.7 4.6
0.008 1056.4 632.9 3.33 1.42 11.7 -4.0 0.7 2354 32.5 6.7 4.7
0.009 1057.2 633.7 3.36 1.41 11.8 -2.5 0.7 2366 32.7 6.7 4.7
0.010 1057.6 633.8 3.34 1.41 11.7 -1.8 0.7 2359 32.6 6.7 4.7
Plots : Fig. 9.16 U vs Concentration; Fig. 9.18 χU vs Concentration; Fig. 9.20 CE vs Concentration;
Fig. 9.17 κ vs Concentration; Fig. 9.19 πi vs Concentration;
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TABLE 9.15
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE), ACOUSTIC IMPEDANCE (Z) AND LENARD JONES POTENTIAL (LJP) AT VARIOUS
CONCENTRATIONS OF IODINE MONOCHLORIDE - ANISOLE SYSTEM
Solvent : n-hexane
Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105 LJP
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 1048.8 634.1 3.29 1.43 11.8 -17.9 0.8 2358 32.5 6.7 4.4
0.002 1050.2 634.7 3.31 1.43 11.9 -15.4 0.7 2365 32.5 6.7 4.5
0.003 1051.0 634.9 3.31 1.43 11.8 -13.9 0.7 2362 32.5 6.7 4.5
0.004 1051.6 634.8 3.32 1.42 11.8 -12.9 0.7 2363 32.5 6.7 4.5
0.005 1052.0 634.1 3.32 1.42 11.8 -12.2 0.7 2360 32.5 6.7 4.5
0.006 1052.4 635.0 3.30 1.42 11.7 -11.5 0.7 2356 32.4 6.7 4.5
0.007 1052.8 634.9 3.31 1.42 11.7 -10.8 0.7 2359 32.5 6.7 4.5
0.008 1054.0 635.7 3.32 1.42 11.7 -8.6 0.7 2361 32.5 6.7 4.6
0.009 1054.4 635.4 3.32 1.42 11.7 -7.9 0.7 2362 32.5 6.7 4.6
0.010 1055.2 635.1 3.33 1.41 11.7 -6.5 0.7 2361 32.5 6.7 4.6
Plots : Fig. 9.16 U vs Concentration; Fig. 9.18 χU vs Concentration; Fig. 9.20 CE vs Concentration;
Fig. 9.17 κ vs Concentration; Fig. 9.19 πi vs Concentration;
Page 308
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TABLE 9.16
ULTRASONIC VELOCITY (U), DENSITY (ρρρρ), VISCOSITY (ηηηη), ADIABATIC COMPRESSIBILITY (κκκκ), ABSORPTION
COEFFICIENT (αααα/f2), MOLECULAR INTERACTION PARAMETER (χχχχU), FREE LENGTH (Lf), INTERNAL PRESSURE (ππππi),
COHESIVE ENERGY (CE), ACOUSTIC IMPEDANCE (Z) AND LENARD JONES POTENTIAL (LJP) AT VARIOUS
CONCENTRATIONS OF IODINE MONOCHLORIDE - 1,4-DIOXANE SYSTEM
Solvent : n-hexane
Temperature : 303 K
C U ρρρρ η η η η /10-4 κ /κ /κ /κ /10-9 α/f2 /10-15 χχχχU /10-3 Lf ππππi CE Z /105 LJP
M ms-1 kg m-3 Nsm-2 kg-1ms2 Npm-1s2 ms-1 Ao atm kJ mol-1 kg-2 s-1
0.001 1056.4 636.1 3.4 1.4 11.81 -3.63 0.7 2381 32.7 6.7 4.7
0.002 1055.6 635.8 3.3 1.4 11.76 -5.19 0.7 2372 32.6 6.7 4.6
0.003 1055.2 636.4 3.3 1.4 11.73 -5.99 0.7 2370 32.5 6.7 4.6
0.004 1054.4 637.0 3.4 1.4 11.80 -7.54 0.7 2378 32.6 6.7 4.6
0.005 1054.0 635.9 3.3 1.4 11.80 -8.33 0.7 2373 32.6 6.7 4.6
0.006 1052.8 635.6 3.3 1.4 11.81 -10.64 0.7 2369 32.6 6.7 4.5
0.007 1054.4 636.3 3.3 1.4 11.81 -7.67 0.7 2375 32.6 6.7 4.6
0.008 1055.2 635.9 3.3 1.4 11.77 -6.21 0.7 2371 32.6 6.7 4.6
0.009 1054.4 636.7 3.4 1.4 11.83 -7.76 0.7 2378 32.6 6.7 4.6
0.010 1053.6 636.8 3.3 1.4 11.81 -9.31 0.7 2374 32.6 6.7 4.6
Plots : Fig. 9.16 U vs Concentration; Fig. 9.18 χU vs Concentration; Fig. 9.20 CE vs Concentration;
Fig. 9.17 κ vs Concentration; Fig. 9.19 πi vs Concentration;
Page 309
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TABLE 9.17
MEAN VALUES OF RELAXATION TIME (t), MEAN VALUES OF GIBB'S FREE ENERGY
OF FORMATION (∆G) AND MEAN VALUES OF FORMATION CONSTANT (K) FOR
IODINE - PHENOLS CHARGE TRANSFER COMPLEXES IN DIFFERENT SOLVENTS AT 303 K
Solvent :- Dichloromethane Chloroform
ττττ /10-13 ∆G ∆G# K ττττ /10-13 ∆G ∆G# K DONOR
s kJ mol-
1 kJ mol-1 dm-3 mol-1 s
kJ mol-1
kJ mol-1
dm-3
mol-1
Diphenyl ether 5.4 -13.8 3.4 236.7 6.9 -13.3 4.0 197.8
4-Chloroanisole 5.4 -10.6 3.4 72.2 6.8 9.7 4.0 53.8
Anisole 5.4 -10.5 3.4 69.6 6.8 -9.7 4.0 51.2
1,4-Dioxane 5.5 -9.7 3.4 52.1 6.9 -9.0 4.1 42.6
Solvent :- Carbon tetrachloride n-Hexane
ττττ /10-13 ∆G ∆G# K ττττ /10-13 ∆G ∆G# K DONOR
s kJ mol-
1 kJ mol-1 dm-3 mol-1 s
kJ mol-1
kJ mol-1
dm-3
mol-1
Diphenyl ether 9.5 -10.0 4.9 57.9 6.3 -9.3 3.8 47.6
4-Chloroanisole 9.6 -9.7 5.0 48.6 6.3 -9.2 3.8 40.0
Anisole 9.4 -9.2 4.9 38.5 6.3 -8.9 3.8 35.4
1,4-Dioxane 9.6 -9.0 5.0 36.1 6.3 -8.6 3.8 32.0
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TABLE 9.18
POLARIZABILITY (α), DIPOLE MOMENT (µ) AND DIELECTRIC STRENGTH (ε)
DIELECTRIC STRENGTH (ε) OF DONORS OF SOLVENTS
Donor α/10α/10α/10α/10-30 µµµµ ε Solvent ε
m3 Debye
Diphenyl ether 20.86 1.03 2.68 Dichloromethane 9.08
4-Chloroanisole 14.75 1.62 7.84 Chloroform 4.81
Anisole 13.07 1.08 4.30 Carbon tetrachloride 2.24
1,4-Dioxane 10.00 0.00 2.22 n-Hexane 1.89
Page 311
Fig. 9.1 Plots of Ultrasonic velocity vs Concentration
1044
1046
1048
1050
1052
1054
1056
0.000 0.002 0.004 0.006 0.008 0.010 0.012
Concentration, M
U,
m s
-1IC-DPEIC-CANIC-ANSIC-DOX
Solvent : dichloromethane Temperature : 303 K
Fig. 9.2 Plots of Adiabatic compressibility vs Concentration
0.710
0.714
0.718
0.722
0.726
0.730
0.000 0.002 0.004 0.006 0.008 0.010 0.012
Concentration, M
κκ κκ /
10
-9,
kg
-1m
s2
IC-DPE
IC-CAN
IC-ANS
IC-DOX
Solvent : dichloromethane Temperature : 303 K
Page 312
312
Fig. 9.3 Plots of Molecular interaction parameter vs
Concentration
-18
-14
-10
-6
-2
2
0.000 0.002 0.004 0.006 0.008 0.010 0.012
Concentration, M
χχ χχU/1
0-3, m
s-1
IC-DPE
IC-CAN
IC-ANS
IC-DOX
Solvent : dichloromethane Temperature : 303 K
Fig. 9.4 Plots of Internal pressure vs Concentration
4840
4860
4880
4900
4920
4940
4960
4980
5000
0.000 0.002 0.004 0.006 0.008 0.010 0.012
Concentration, M
ππ ππi, a
tm
IC-DPE
IC-CAN
IC-ANS
IC-DOX
Solvent : dichloromethane Temperature : 303 K
Page 313
313
Fig. 9.5 Plots of Cohesive energy vs Concentration
33.2
33.4
33.6
33.8
34.0
34.2
0.000 0.002 0.004 0.006 0.008 0.010 0.012
Concentration, M
CE
, kJ m
ol-1
IC-DPE
IC-CAN
IC-ANS
IC-DOX
Fig. 9.6 Plots of Ultrasonic velocity vs Concentration
958
960
962
964
966
968
0.000 0.002 0.004 0.006 0.008 0.010 0.012
Concentration, M
U,
m s
-1
IC-DPE
IC-CANIC-ANS
IC-DOX
Sovent : chloroform Temperature : 303 K
Page 314
314
Fig. 9.7 Plots of Adiabatic compressibility vs Concentration
0.752
0.756
0.760
0.764
0.768
0.772
0.000 0.002 0.004 0.006 0.008 0.010 0.012
Concentration, M
κκ κκ /
10
-9,
kg
-1m
s2
IC-DPE
IC-CAN
IC-ANS
IC-DOX
Sovent : chloroform
Fig. 9.8 Plots of Molecular interaction parameter vs
Concentration
-20.0
-15.0
-10.0
-5.0
0.0
5.0
0.000 0.005 0.010 0.015
Concentration, M
χχ χχU/1
0-3
, m
s-1
IC-DPE
IC-CAN
IC-ANS
IC-DOX
Sovent : chloroform Temperature : 303 K
Page 315
315
Fig. 9.9 Plots of Internal pressure vs Concentration
4060
4070
4080
4090
4100
4110
4120
4130
0.000 0.002 0.004 0.006 0.008 0.010 0.012
Concentration, M
ππ ππi,
atm
IC-DPE
IC-CAN
IC-ANS
IC-DOX
Sovent : chloroform
Fig. 9.10 Plots of Cohesive energy vs Concentration
34.6
34.8
35.0
35.2
35.4
0.000 0.002 0.004 0.006 0.008 0.010 0.012
Concentration, M
CE
, kJ m
ol-1
IC-DPE IC-CAN
IC-ANS IC-DOX
Sovent : chloroform
Page 316
316
Fig. 9.11 Plots of Ultrasonic velocity vs Concentration
896
900
904
908
912
916
0.000 0.002 0.004 0.006 0.008 0.010 0.012
Concentration, M
U m
s-1
IC-DPE IC-CANIC-ANS IC-DOX
Sovent : carbon tetrachloride Temperature : 303 K
Fig. 9.12 Plots of Adiabatic compressibility vs Concentration
0.78
0.79
0.80
0.81
0.82
0.000 0.002 0.004 0.006 0.008 0.010 0.012
Concentration, M
κκ κκ /
10
-9,
kg
-1m
s2
IC-DPE IC-CANIC-ANS IC-DOX
Sovent : carbon tetrachloride Temperature : 303 K
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317
Fig. 9.13 Plots of Molecular interaction parameter vs
Concentration
-15
-9
-3
3
9
15
0.000 0.002 0.004 0.006 0.008 0.010 0.012
Concentration, M
χχ χχU, m
s-1
IC-DPE IC-CANIC-ANS IC-DOX
Sovent : carbon tetrachloride
Fig. 9.14 Plots of Internal pressure vs Concentration
3740
3760
3780
3800
3820
3840
0.000 0.002 0.004 0.006 0.008 0.010 0.012
Concentration, M
ππ ππi,
atm
IC-DPE IC-CAN
IC-ANS IC-DOX
Sovent : carbon tetrachloride Temperature : 303 K
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318
Fig. 9.15 Plots of Cohesive energy vs Concentration
38.4
38.6
38.8
39.0
39.2
39.4
0.000 0.002 0.004 0.006 0.008 0.010 0.012
Concentration, M
CE
, kJ m
ol-1
IC-DPE IC-CANIC-ANS IC-DOX
Sovent : carbon tetrachloride Temperature: 303 K
Fig. 9.16 Plots of Ultrasonic velocity vs Concentration
1044
1048
1052
1056
1060
0.000 0.002 0.004 0.006 0.008 0.010 0.012
Concentration, M
U,
m s
-1
IC-DPE IC-CANIC-ANS IC-DOX
Sovent : n-hexane Temperature : 303 K
Page 319
319
Fig. 9.17 Plots of Adiabatic compressibility vs Concentration
1.40
1.42
1.44
1.46
0.000 0.002 0.004 0.006 0.008 0.010 0.012
Concentration, M
κκ κκ /
10
-9,
kg
-1m
s2
IC-DPE IC-CANIC-ANS IC-DOX
Sovent : n-hexane Temperature : 303 K
Fig. 9.18 Plots of Molecular interaction parameter vs
Concentration
-25
-20
-15
-10
-5
0
0.000 0.002 0.004 0.006 0.008 0.010 0.012
Concentration, M
χχ χχU, m
s-1
IC-DPE IC-CANIC-ANS IC-DOX
Solvent : n-hexane Temperature : 303 K
Page 320
320
Fig. 9.19 Plots of Internal pressure vs Concentration
2300
2320
2340
2360
2380
2400
0.000 0.002 0.004 0.006 0.008 0.010 0.012
Concentration, M
ππ ππi, a
tm
IC-DPE IC-CAN IC-ANS IC-DOX
Solvent : n-hexane Temperature : 303 K
Fig. 9.20 Plots of Cohesive energy vs Concentration
32.3
32.4
32.5
32.6
32.7
32.8
0.000 0.002 0.004 0.006 0.008 0.010 0.012
Concentration, M
CE
, kJ m
ol-1
IC-DPE IC-CANIC-ANS IC-DOX
Solvent : n-hexane
Page 322
322
CHAPTER – 10
SUMMARY
This thesis deals with ultrasonic studies on binary and ternary liquid
systems. The main aim of the present investigation is to distinguish
different types of intermolecular forces of attraction. The formation
constants of donor acceptor complexes formed between iodine and several
organic compounds are determined through ultrasonic velocity
measurement. Similar studies are also made in ternary systems containing
iodine monochloride and several organic compounds in n-hexane medium at
303 K. In the first chapter, the nature of ultrasound, measurement of
ultrasonic velocity and applications of ultrasound in various fields are
briefly outlined. The present work deals with charge transfer complexes and
hence, different types of donors, acceptors and donor-acceptor complexes
are indicated. The methods employed for the determination of such
complexes and the factors which influence the formation of CT complexes
are also described in this chapter.
The experimental details including materials used, their purification
and instrumental details are explained in the second chapter. The relevant
equations employed for computing the acoustical parameters and excess
properties are presented in the third chapter.
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323
Ultrasound scan in liquid mixtures can be used to distinguish
different types of intermolecular attraction. In order to establish this,
ultrasonic velocity measurements were made in the following binary liquid
mixtures:
Benzene-carbon tetrachloride, bromobenzene-chlorobenzene,
ethanol-water, ethanol-p-cresol, ethanol-phenol and ethanol-pyridine.
The acoustical properties, excess functions and their trend with
concentration suggest that weak interactions of induced dipole-induced
dipole are present in benzene-carbon tetrachloride system while relatively
strong dipole-dipole attraction exists in bromobenzene-chlorobenzene binary
system. In the other four systems containing ethanol as common
component, ethanol behaves as structure breaker for water clusters and
strong intermolecular hydrogen bonds are present in this system at
moderate concentration. In ethanol-pyridine system, there are strong dipole-
dipole attractions. However, in ethanol-phenol and ethanol-p-cresol
systems, ethanol molecules break the intermolecular hydrogen bonds
present in the phenolic compounds and with increase in the mole fraction of
ethanol, there are strong intermolecular attractions between ethanol and
phenol molecules. The results obtained in these investigations are presented
in fourth chapter and discussed.
Page 324
324
The fifth chapter deals with the ultrasonic investigations of charge
transfer complexes of iodine with six benzene derivatives and three
polynuclear aromatic hydrocarbons. Benzene derivatives used as donors are
benzene, toluene, o-xylene, m-xylene, p-xylene and mesitylene while the
polynuclear aromatic hydrocarbons are naphthalene, biphenyl and
anthracene. The ultrasonic velocity values and other acoustical properties
vary with concentration and these variations establish the formation of
donor-acceptor complexes between iodine and all the nine aromatic
hydrocarbon molecules. The trend in formation constant and free energy of
formation values suggests that the presence of methyl substituent in
benzene enhances the stability of the complex. Steric effect also plays a role
in the complexation and this is evident from stability constant and free
energy of formation values of ortho isomer of xylene as compared to those of
para and meta xylenes. Further, polynuclear aromatic hydrocarbon
molecules are rich in π electrons and hence, they form more stable
complexes than benzene derivatives. Among the polynuclear aromatic
hydrocarbon molecules, the stability constants of the complexes are in the
following order:
anthracene > biphenyl > naphthalene
Iodine monochloride is a dipolar molecule and the positive end of the
dipolar molecule may be attracted by π electrons of aromatic hydrocarbon
molecules. In the sixth chapter, stability constants for the CT complexes of
Page 325
325
iodine monochloride and six benzene derivatives as well as three polycyclic
hydrocarbons are reported. These values are determined by ultrasonic
method. The acoustical properties also establish the formation of CT
complexes in these systems. It is found that the stability constant, free
energy of formation and relaxation time are constant for a given system and
differ from one system to another. The influence of substituents is found to
be similar to that observed in iodine complexes of these donor molecules. It
is also found that iodine monochloride forms more stable complexes with
aromatic hydrocarbons than with iodine.
Seventh chapter deals with the ultrasonic studies on the charge
transfer complexes of iodine and five phenolic derivatives. Acoustical
properties are calculated for the five systems in four different solvents with a
view to study the influence of solvent polarity on the stability of this type of
CT complexes. The variations in the acoustical properties with concentration
establish the formation of CT complexes between iodine and the five
phenols. The trend in the formation constant values indicates that the
presence of electron releasing group like methyl enhances the stability of the
complex. However, when bulky groups like isopropyl is adjacent to the
phenolic group, the stability constant is found to decrease. Slight increase
in polarity of the medium increases the stability of the CT complexes formed
in the five systems.
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326
Eighth chapter contains the results obtained in the ultrasonic
investigation of CT complexes formed between iodine monochloride and five
phenols. Studies are made in four different less polar and non-polar
solvents namely, dichloromethane, chloroform, carbon tetrachloride and n-
hexane. The stability constants of the complexes formed between iodine
monochloride and phenols are calculated by the method of Kannappan. The
trend in the values of formation constants is explained with the known
structural effects. In a given solvent, the trend in the stability constants
indicates that the order of stability is:
o-Cresol > p-cresol > m-cresol > phenol > carvacrol
This order is similar to the trend in the stability constants of iodine
and phenols. The influence of dielectric constant of the medium on the
stability of this type of complexes is also studied. The stability constant of a
particular iodine monochloride-phenol complex increases with increase in
dielectric constant of the solvent.
Iodine monochloride can form CT complexes with ethers. Ethers can
function as n electron donors and in the case of aryl ethers, they can
function as π electron donors also. The results obtained in the ultrasonic
investigation of CT complexes formed between iodine monochloride and four
ethers are summarized in ninth chapter. Formation constants are reported
for CT complexes of iodine monochloride and four ethers in four solvents.
Page 327
327
The trend in stability constants is explained with the structural effects. The
stabilities of these complexes are influenced by the dielectric constant of the
solvent. It is found that stability constant increases with increase in the
dielectric strength of the medium. The stability constants of the sixteen CT
complexes are correlated with the molecular properties of donor molecules.
Polarizability of donor correlates with the formation constants.
The conclusions drawn from the results obtained in all the
investigations and the important findings of the present studies are
summarized in the tenth chapter.
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329
LIST OF PUBLICATIONS
1. Arunkumar, M., Shabeer, T.K., Abdul Mahaboob, P.A., Jayakumar,
S., Kannappan, V. and Ulagendran, V., ‘Acoustical studies on
binary liquid mixtures’ Journal of Acoustical Society of India, Vol.
32, 2004, pp 142.
2. Kannappan, V., Askar Ali, S.J. and Abdul Mahaboob, P.A.,
‘Determination of stability constant of charge transfer
complexes of iodine monochloride and certain ethers in solution
at 303 K by ultrasound method’ Indian Journal of Pure & Applied
Physics, Vol. 44, December, 2006
3. Kannappan, V., Irusan, T., Abdul Mahaboob, P.A., and Askar Ali,
S.J. ‘Solvent effect on the stability constants of charge transfer
complexes of iodine and certain ethers at
303 K’ Journal of Molecular Liquids (Communicated)
Page 330
330
LIST OF PAPERS PRESENTED
1. ‘Determination of stability constant of charge transfer
complexes of iodine and certain ethers in solution at 303
K’ ‘ALPS 2006’ - International Conference on Recent
Advancements in Chemistry, sponsored by Department of
Science and Technology, held at Auxilium College, Vellore,
Tamilnadu State during 5th and 6th January, 2006.
2. ‘Determination of stability constant of charge transfer
complexes of iodine monochloride and certain ethers in
solution at 303 K’ ‘ALPS 2006’ - International Conference on
Recent Advancements in Chemistry, sponsored by Department
of Science and Technology, held at Auxilium College, Vellore,
Tamilnadu State during 5th and 6th January, 2006.
3. ‘Ultrasonic studies on charge transfer complexes of iodine
monochloride and polynuclear aromatic hydrocarbons in
n-hexane solution at 303 K’ - ‘Newchemlinks 2006’ -
National Conference on Eco-, Sono- and Nanochemistry &
Recent Advancements in Chemistry, sponsored by Department
of Science and Technology, New Delhi held at The New College,
Chennai, Tamilnadu State during 20th and 21st December,
2006.
Page 331
331
4. ‘Determination of stability constant of charge transfer
complexes of ethanolamines with tetrachloroethylene in
dimethyl sulphoxide solution by ultrasound method at
303 K’ - ‘Newchemlinks 2006’ - National Conference on Eco-,
Sono- and Nanochemistry & Recent Advancements in
Chemistry, sponsored by Department of Science and
Technology, New Delhi held at The New College, Chennai,
Tamilnadu State during 20th and 21st December, 2006.
5. ‘Determination of stability constant of charge transfer
complexes of polynuclear aromatic hydrocarbons with
iodine in n-hexane 303 K’ – ‘RAMS – 2006’ – National
Conference on Recent Advancements in Materials Science,
Sponsored by UGC, RKM Vivekananda College, Chennai,
Tamilnadu State during 29th and 30th December, 2006.
6. ‘Ultrasonic studies on charge transfer complexes of carbon
tetrachloride and ethanolamines in dimethyl sulphoxide
solution at 303 K’ - ‘RAMS – 2006’ – National Conference on
Recent Advancements in Materials Science, Sponsored by
UGC, RKM Vivekananda College, Chennai, Tamilnadu State
during 29th and 30th December, 2006.
Page 333
333
Indian Journal of Pure & Applied Physics Vol. 44, December 2006, pp. 903-908
Determination of stability constants of charge transfer complexes of
iodine monochloride and certain ethers in solution at 303 K by ultrasonic
method
V Kannappan, S J Askar Ali & P A Abdul Mahaboob
Postgraduate and Research Department of Chemistry, Presidency College (Autonomous), Chennai 600 005
Received 21 February 2006; revised 22 March 2006; accepted 24 October 2006
Ultrasonic velocities (U), densities (ρ), and coefficient of viscosities (η) are measured for solutions
containing iodine monochloride (ICl) and one of the following ethers in equimolar concentration in the range
0.001-0.01M at 303 K. The diphenyl ether, 4-chloroanisole, anisole and 1,4-dioxane are used as donors and the
dichloromethane, chloroform, carbon tetrachloride and n-hexane have been used as solvents. Acoustical
parameters such as adiabatic compressibility (β), absorption coefficient (α/f2), internal pressure (πi) and
cohesive energy (CE) values are calculated from the measured values of U, ρ and η. The trend in the acoustical
parameters establishes the formation of charge transfer complexes between iodine monochloride (acceptor) and
ethers (donors). The stability constants (K) are calculated for these complexes. The free energy changes (∆G)
for the formation of these complexes are also calculated from K values. The formation constants with
polarizability, dielectric strength and dipole moment of the donor and solvent molecules have been correlated.
The free energy of activation (∆G#) and viscous relaxation time (τ) are found to be almost constant for these
complexes indicating the formation of similar charge transfer complexes in these systems.
Keywords: Ultrasonic velocity, Formation constants, Donor-acceptor complexes, Iodine monochloride, Ethers
IPC Code: B01J19/10
