THE REACTIVITY OF METHYLENE BLUE TOWARDS

SILVER NITRATE AND MERCURY(II) CHLORIDE

A dissertation submitted to the

BHARATHIDASAN UNIVERSITY,

in partial fulfillment of the requirements

for the award of the degree of

MASTER OF SCIENCE

IN CHEMISTRY

By

M. Mohan Raj

(Regd.No. 2002MS05)

DEPARTMENT OF CHEMISTRY

BHARATHIDASAN UNIVERSITY

TIRUCHIRAPPALLI- 620 024

May 2004

Department of Chemistry, Bharathidasan

University,

Tiruchirappalli - 620 024, India

___________________________________

Dr. K. Panchanatheswaran, M.Sc., Ph.D(Hawaii) May , 2004

Professor

CERTIFICATE

This is to certify that the dissertation entitled “The Reactivity of

Methylene Blue Towards Silver Nitrate and Mercury(II) Chloride”

submitted in partial fulfilment for the degree of Master of Science in

Chemistry to Bharathidasan University, under the semester system, is a

bonafide record of work done by Mr. M. Mohan Raj (Reg.No :

2002MS05) under my supervision and guidance and that the dissertation

has not previously formed the basis for the award of any degree, diploma,

associateship, fellowship or other similar titles.

(K. Panchanatheswaran)

Table of Contents

Acknowledgement I

Abstract II

List of Tables III

List of Figures IV

Introduction 1

Scope of the Work 12

Experimental Aspects

1). Instrumentation 13

2). Synthetic Chemistry 14

Results and Discussion 16

Conclusion 42

References 43

ACKNOWLEDGEMENT

It is with great pleasure that I thank my guide Dr. K.

Panchanatheswaran, Professor, for his valuable guidance, unstinted

support, useful discussions and constant encouragement throughout

the course of this study.

Dr. M. Palaniandavar, Professor and Head, Department of

Chemistry, is gratefully thanked for having provided the necessary

facilities.

My sincere thanks are due to all the faculty members,

research scholars and the non-teaching staff for their

encouragement.

Ms. S. Jose Kavitha spent her valuable time in solving the

crystal structure of the one of the products, I thank and acknowledge

her services.

With profound gratitude Mr. T. R. Sarangarajan, Lecturer,

SASTRA, Thanjavur and Mr. S. Chandrasekar, Lecturer,

Government Arts College, Ariyalur are thanked for their support. I am

very happy to thank my seniors Ms. M. Baby Mariyatra, Mr. E.

Mothi Mohamed, and Mr. B. S. Krishnamoorthy for their

support and help.

I offer my special thanks to my colleague, Ms. P. Suguna, for

boosting my spirits, and to my friends, classmates and juniors for

providing me support and comfort.

I am greatly indebted to my parents and sister for their love for

me without which the completion this work would not have been

possible. Above all, I thank God Almighty for His merciful blessings

(M. MOHAN RAJ)

ABSTRACT

The reaction of Methylene Blue with silver nitrate has yielded a

violet solid, soluble in water, methanol and ethanol. Recrystallization

of the product in water gave the diffraction quality crystals. Single

crystal X-ray investigations were used to determine the crystal and

molecular structure of the product. The compound crystallized in the

space group P-1, whose structure was found to contain Methylene

Blue cation and nitrate anion along with two water molecules. Several

intermolecular attractions involving N-H…O, C-H…O and pi-pi

interactions have been found in the product. Analogous reaction with

mercury(II) chloride gave violet brown solid. Attempts to crystallize

the product were not successful. The product was formulated to be

either a complex of Methylene Blue with mercury (II) chloride or one

with Methylene Blue cations and tetrachloromercurate anion. The

leuco base of Methylene Blue was obtained by its reaction with silver

nitrate and mercury(II) chloride. The colourless solids were not

characterized completely.

List of Tables

_________________________________________________

Title Page No.

_________________________________________________

1. Examples of Antipsychotic Phenothazine Drugs 9

2. UV Spectral data for Methylene Blue and its

‘Product’ with Silver Nitrate. 23

3. Bond Lengths in Methylene Blue Derivatives 24

4. Bond Angles in Methylene Blue Derivatives 25

5. Crystal data and structure refinement for 3,7-Bis

(dimethylamino)phenothiazin-5-ium nitrate dihydrate. 26

6. Atomic coordinates (× 104) and equivalent isotropic

displacement parameters (.°2×103 ) for Methylene

Blue Nitrate. 27

7. Bond lengths [A°] and angles [°] for Methylene Blue

Nitrate. 28

8. Anisotropic displacement parameters (.°2×103) for

Methylene Blue Nitrate. 30

9. Hydrogen coordinates ( X 104 ) and isotrpic displacement

parameters (.°2×103) for Methylene Blue Nitrate. 31

10. Hydrogen bonds for Methylene Blue Nitrate. 32

11. Analytical data for the products obtained by the

reactions of Methylene Blue with AgNO3 and HgCl2. 33

List of Figures

Title Page No.

1. Structures of Phenothiazine drugs. 4

2. Structures of Methylene Blue derivatives. 6

3. Atom numbering scheme in Methylene Blue derivatives 7

4. IR spectrum of Methylene Blue 19

5. IR spectrum of the Methylene Blue Nitrate. 20

6. UV-Visible spectrum of Methylene Blue. 21

7. UV-Visible spectrum of Methylene Blue Nitrate. 22

8. Molecular structure of Methylenes Blue Nitrate with 50%

probability displacement ellipsoids 34

9. Packing diagram of the molecules showing the interlinking

of the stacked aromatic moieties by N-H…O and

C-H…O hydrogen bonds. 35

10. Packing diagram showing the one-dimensional chain along a

axis formed by the nitrate ions and the water molecules 36

11. Packing diagram showing the one-dimensional chain

linking the aromatic moieties and the hydrogen bonding

interaction involving N(10) of the aromatic ring, nitrate

and the water molecules. 37

12. Packing diagram showing the supramolecular network

of the molecules with the one-dimensional chains linking

the adjacent stacked aromatic moieties, the chains being

interlinked via C-H…O hydrogen bonds. 38

13. IR spectrum of the product between Methylene Blue and

Mercury(II) Chloride. 39

14. IR spectrum of the product between Leucomethylene

Blue and Silver Nitrate. 40

15. IR spectrum of the product between Leucomethylene

Blue and Mercury(II) Chloride 41

CHAPTER I

Introduction

INTRODUCTION

Methylene Blue: Historiography1

Methylene Blue was first synthesized by the German chemist

Heinrich in 1876. Robert Koch discovered the tubercle bacillus with

the help of Methylene Blue. Paul Ehrlich who later discussed the anti-

syphilis drug, Salvarsan, noticed that the dye imparted colour only to

the carriers of illnesses and at the same time destroy them without

attacking the body’s own cells. The revolutionary idea led to the

development of chemotherapy, one of the greatest advances in

medical science. Methylene Blue is not only a good colouring agent

for living cells but also an excellent redox indicator in aqueous

solution as indicated below.

SNN23N(CH)32(CH)

NS)N(CH32)(CH23N+

............................reductionoxidationClH2+.HClmethylene blue(blue)

leucomethylene blue(colorless)

H

The redox system of Methylene Blue – Leucomethylene Blue

Preparation of Methylene Blue2:

Methylene Blue, 3,7-bis-(dimethlamino)phenothiazonium

chloride is by the far the most important phenothiazine dyestuff and is

prepared by the oxidation of N,N-dimethyl-p- phenylenediamine in

situ with sodium thiosulfate , sulfuric acid and sodium dichromate at

0°C under carefully controlled conditions. Further dimethylamine is

then added together with more dichromate to form the green indamine

thiosulfonic acid, which is finally treated with copper(II) sulfate and

further quantity of dichromate at 60-70°C to give Methylene Blue.

222233NMe222NMeMeNNMe2NMe2NMe2NMe2NMe2NHNHNMe22SOSH3SOSH+........

NaSOO___

_

................

__

__

O2)

NSN(CH3)(CH23NHNNMe22

....................

SOCu4NS2MeN2MeN2MeN2MeN2MeN

....................

___

_

O+

HSO3Methylene blue(Indamine Thiosulfonic acid)

Leuco methylene blue

The dyestuff may be isolated as the sparingly soluble zinc

chloride double salt after first screening off the insoluble chrome

residues. Medicinal quality Methylene Blue is obtained by a further

recrystallisation from dilute hydrochloric acid and brine. An

alternative and versatile laboratory synthesis of 3,7-diamino-

substituted phenothiazine dyes is based upon the reaction of

3,7-dibromophenothiazonium bromide prepared from phenothiazine

with amines.

Phenothiazine Dyes2:

Phenothiazine dyes are mostly salts of the oxidized form of

3,7-diaminophenothiazine with substituents on the amino groups. The

first phenothiazine dye to be made was 3,7-di-aminophenothiazonium

chloride, known as Lauth’s violet.

Methylene Blue3:

SNNN3CH3CH3CHH3C+

Cl H_

O2

New Methylene Blue NXX:

SNEtNH+

MeNHEtMeCl

Toluidine Blue:

MeSNNH22MeN2MeN2MeN2MeN2MeN+

Cl

Methylene Blue:

Cl+NMe2NMe2NMe2NMe2NMe2NHSNMeMe

Brilliant Alizarine Blue G:

OHOHSO3_

2MeN2MeN2MeN2MeN2MeN+

SN

Fig. 1. Structures of Phenothiazine Dyes2

Leuco-Methylene Blue2:

A pale yellow water insoluble solid. (m.p 185°C) may be

obtained from the indaminethiosulfonic acid precursor by boiling an

aqueous solution with dilute acid or more conveniently, by reduction

of Methylene Blue in aqueous solution with sodium dithionite. It is

readily re-oxidised to Methylene Blue on exposure to air and can be

N-acylated. Thus N-benzoyl-leuco-Methylene Blue is obtained by

benzoylation of leuco-Methlyene Blue with benzoyl chloride in

pyridine, in aqueous alkaline medium, or in a variety of water-

immiscible solvents.

Benzoyl-leuco-Methylene Blue is used in carbonless, pressure-

sensitive copying papers. In these systems it is dissolved, along with

other “color formers”, for example Crystal Violet Lactone, in a non-

polar high boiling solvent and the solution is encapsulated in gelatin

walled microcapsules. The suspension of capsules is applied to the

underside of a sheet of paper. Application of pressure, by either

writing or typing, to this paper causes the impression to a second,

underlying, sheet of paper the upper surface of which is coated with

an “acidic” material, generally an activated mineral such as silica or

attapulgite clay. A methylene Blue print is formed by hydrolysis of

the N-benzoyl group on the active surface and subsequent aerial

oxidation of the Leucomethylene Blue so produced.

Methylene Blue forms several derivatives containing different

anions whose structures were determined by X-ray Crystallography.

The following are examples.

Methylene Blue thiocyanate4:

+

C3HCH3CH3CH3NNSNNCS_

Methylene Blue urate hydrate5:

SNNN3CH3CH3CHH3C+

HNNNHNHOOO2OH

Fig. 2. Methylene Blue Derivatives

Bis(malenonitrilethiolato)-copper(II)bis(3,9-

bis(dimethylamino)phenazathionium) acetone solvate6:

+

C3HCH3CH3CH3NNSNC3HO+2NCCNNCCNCuSSSS3CH

Fig. 2. Methylene Blue Derivatives

O............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

OOO

..................................................................................................................................................................

..................

C1CCCCCCCCCCCCCCSC2345687911121314NN10N3132717237

Fig. 3. Atom numbering Scheme in Methylene Blue Derivatives

Phenothiazine Drugs7

Antipsychotic Agents:

Drug substances, which depress Central Nervous System and are

able to calm severely disturbed psychiatric patients without affecting

consciousness or causing any neurological effects are called antipsychotic

agents. They produce strong sedation without inducing sleep and cause a

state of indifference.

Phenothiazine Derivatives

Many phenothiazine derivatives have been synthesized and several

of them are useful in the treatment of psychotic states. Chlorpromazine is

one of the derivatives, which was effective in the treatment of various

psychotic disorders and also efficacious against nausea and vomiting.

Some fairly consistent patterns of relation between structure and

antipsychotic activity among individual classes of compounds has been

noted. Stereochemical and conformational considerations are important for

determination of psychotropic activity. In addition, water solubility, lipid-

water partitioning acid-base properties and surface activity have been

established to play a significant role in exhibiting potent antispychotic

properties.

A third carbon unbranched side chain gives the most active compound

in tranquilizing area i.e. amino group separated by third carbon atoms is

optimal for antipsychotic activity. A basic tertiary amino moiety provides

maximum antipsychotic potency 7.

Generic and

Proprietary

Name

Chemical

Name

Side Chain

R

R1

Chloropromazine

(Thorazine,

Largatil)

2-Chloro-10 (3-dimethyl-

amnio)-

propylphenothazine,II

-(CH2) 3-(NH3) 2

Cl

Promazine

(sparine)

10-(3-dimethylamino)-

propyl-phenothiazine,III

-(CH2) 3-N (NH3)2

H

Triflupromazine

(vesprin)

10-(3-dimetylamino)-

propyl)-2-(trifluoromethyl-

phenothiazine, IV

-(CH2) 3-N(NH3)2

CF3

Promethazine

(Phenergan)

10-(2-Dimethylaminopropyl)

phenothiazine, V

N(CH2)CHCH3(CH3)2

H

Trifluoperazine

(Stelazine)

10(3-(4-methyl-)piperazinyl))

Propyl-2-

trifluoromethylphenothiazine,

VI

NNCH33()CH2

CF3

Prochloroperazine

(Compazine)

2-chloro-10 (3-(4-methyl-1-

piperazinyl))-propyl

phenothiazine, VII

NNCH33()CH2

Cl

Fluphenazine

(Permititil,Prolixin)

10-(3-(4-(2-hydroxyethyl)

piperazinyl)

propyl)-2-trifluoromethyl

phenothiazine, VIII

CH2)(3NNH2CC2HHO

CF3

Mosoridazine

(Serentil)

10-2-(1-methylsulfinyl)

Phenothiazine,IX

N3()CH2CH3

OSCH

Table 1: Examples of Antipsychotic Phenothiazine

Drugs7

The Biological and Analytical Chemistry of

Methylene Blue

The dye methylene blue (MB) is widely used as a stain and has

a number of biological uses as discussed below8. It can be used to treat

urinary tract infections, to distinguish between cancerous and normal tissue

and it has potential as a prophylactic treatment for Alzheimer’s disease.

The metabolism and excretion of MB in living organisms was the subject

of a number of investigations the earliest dating back to 1885. Early

investigations showed that MB was eliminated form the body in unchanged

from as well as in some leuco- dye forms. A detailed investigation was

carried out in 1972 which confirmed these studies. It was shown that

extracts of urine from human patients dosed with 10 mg sample of MB

contained MB but also a leuco- dye form.The reaction between

Chondroitin 4-Sulfate with Methylene Blue has been studied9. The results

show that via an electrostatic interaction Methylene Blue aggregates on

Chondroitin 4-Sulfate as concluded by CD spectra .

_______________________

Structure of Chondroitin 4-Sulfate

n)(

HOHHOOOOSO3HCCHOH2HCOOHOOOOHO+NaCNHO

Methylene Blue has well established photochemical properties and

has been used in a variety of photochemical applications including

photodynamic therapy(PDT)10, based on the property of cetain

biocompatible sensitizers to generate reactive species when they absob

light, resulting in the destruction of neighboring biomolecules and cell

death.

Methylene Blue is used as a redox indicator in the estimation of

titanium(III) chloride, in place of starch in iodometric titrations; its

insoluble perchlorate and dichromate can serve as the basis of gravimetric

determinations2. Methylene Blue can be oxidised by ammonium persulfate

in presence of Au(III). This serves as the basis for the determination

Pd(II)11. Arsenic can be determined in parts-per-million (ppm) level by

absorbance measurement. This method is based on the quantitative colour

bleaching of the dye, Methylene Blue by arsine catalysed by Ag or Au

nano particles in micellar medium. This arsine has been generated in situ

from sodium arsenate by sodium borohydride reduction. The absorbance

measurement was carried out at the .max of the dye at 660 nm12. Methylene

Blue can be reduced to the leuco-base form by reduction with ascorbic acid

also13.

CHAPTER II

Scope of the Work

Scope of the work

Methylene Blue is a cationic dye and important for its analytical and

biological applications. It will be interesting to know about its reactions

towards its metal salts, No metal complexes of Methylene Blue is known at

present, although it has many sites for coordination. The structural unit of

Methylene Blue viz, phenothiazine is present in many psychiatric drugs.

The leuco base of Methylene Blue can also be prepared by the reaction

with reducing agents. This can also react with metal salts, perhaps in

different fashion.

Extraction of palladium from the nuclear waste of the power plants is

one of the current challenges in nuclear chemistry. Making use of the

known affinity of sulfur to Pd2+, sulfur based extractants are proposed for

the above purpose. The interaction of Methylene Blue, a sulfur containing

heterocyclic compound, with both Ag+ & Hg2+ is studied. The above ions

closely resemble Pd2+ and are chosen for model studies. In order to

ascertain the interaction of Ag+ & Hg2+, the reactions of Methylene Blue

with AgNO3 and HgCl2 have been attempted.

CHAPTER III

Experimental Aspects

Experimental Aspects

1. Instrumentation

The IR spectrum was taken as KBr pellets using Perkin Elmer FTIR

spectrophotometer at the Department of Chemistry, Bharathidasan

University, Tiruchirappalli. The UV-Visible spectra were recorded using

carry 300-model Varian UV-Visible spectrophotometer at the Department

of Chemistry, Bharathidasan University, Tiruchirappalli. X-ray intensisty

data were collected using the EPSRC National Crystallographic Services

Southampton, England with Brucker Nonius KappaCCD area detector.

The structure solution and refinement were carried out using the following

programs, SHELXS97 and SHELXL97. Molecular diagrams were obtained

with ORTEP3 package using 50 % probability thermal ellipsoids for the

non hydrogen atoms and PLATON97 package.

2. Synthetic Chemistry

(i) Reaction of Silver Nitrate with Methylene Blue

Silver nitrate (0.339 g, 2 mmol) and Methylene Blue (0.373 g, 1

mmol) were mixed in 40 ml of water. The mixture was stirred for half an

hour. Diffraction quality violet crystals were obtained upon complete

evaporation of water. m.p >280°C.

IR (cm-1): 3418, 1599, 1486, 1443, 1384, 1356, 252, 1176, 1147, 1082,

961, 884, 814, 612.

(ii) Reaction of Mercury(II) Chloride with Methylene Blue

Mercury(II) chloride (0.145 g, 1 mmol) was dissolved in methanol

and Methylene Blue (0.2 g, 1 mmol) in water was added to it. The mixture

was stirred for few minutes. The brown solid was filtered off. m.p >280°C.

Yield: 73%.

IR (cm-1): 3463, 1599, 1491, 1436, 1398, 1336, 1241, 1219, 1177, 1138,

1056, 1035, 948, 886, 851, 821, 663.

(iii) Preparation of Leucomethylene Blue

Sodium hydroxide (0.2 g) was added to 50 ml of water in a round-

bottomed flask followed by 0.09 g of glucose. The mixture was treated

with Methylene Blue (0.186 g, 1 mmol) in water. The mixture was heated

in steps of 10°C up to 50°C. The blue coloured solution became colourless.

This indicated the formation of Leucomethylene Blue, which was found to

be unstable to air.

(iv). Reaction of Mercury(II) Chloride with Leucomethylene Blue

Mercury(II) chloride(0.135 g, 1 mmol) was dissolved in methanol

and to that aqueous solution of Leucomethylene Blue (which was prepared

by procedure (iii)) was added. The mixture was stirred for some time and

filtered. The filtrate was evaporated to give rose red solid. m.p >280°C.

IR (cm-1): 1634, 1454, 1382, 1089, 879.

(v) Reaction of Silver Nitrate with Leucomethylene Blue

Silver nitrate (0.0844 g, 1 mmol) was dissolved in water and to

that aqueous solution of Leucomethylene Blue (which was prepared by

procedure (iii)) was added. The mixture was stirred for some time and

filtered. The filtrate was evaporated to give rose red solid. m. p >280°C.

IR (cm-1): 3439, 2920, 1642, 1382, 1154, 1071, 1024, 879.

CHAPTER IV

Results and Discussion

Results and Discussion

Reaction of Silver Nitrate with Methylene Blue:

The product is insoluble in chloroform whereas Methylene Blue is

partially soluble in chloroform. The IR spectrum of the product shows

features very different from that of Methylene Blue (Fig. 4 & 5).

The spectrum has peaks due to Methylene Blue and the nitrate ion. The

peak at 961 cm-1 which is absent in Methylene Blue, shows the presence of

nitrate ion. The UV spectra of Methylene Blue nitrate indicates Red shift

of absorption to 293 nm with respect to the absorption at 259 nm in

Methylene Blue itself (Fig. 6 & 7)(Table. 2). In order to assign the

structure of the solid X-ray Crystallographic investigation was undertaken.

The Ortep diagram of the product is shown in (Fig. 8). The X-ray crystal

structure shows that the product (1) Methylene Blue nitrate consists of

Methylene Blue cation, nitrate anion and two water molecules. The

Methylene Blue cation can be represented by structures I and II.

(CH3)2NNSN(CH3)2+N(CH3)2SN(CH3)2N+

I II

Structure II is predominant in the chloride and thiocyanate salts.

The cation of the product adopts structure II as evident from the

pronounced shortening of bonds C1-C2 (1.359(4) A°) and C4-C12

(1.373(4) A°) compared with the other carbon-carbon bonds. The two C-S

bonds are equal in length, supporting that structure II is more appropriate

).2Hfor the cation. The bond lengths and angles are comparable to those of

other Methylene Blue derivatives (Table 3 & 4). The relevant

crystallographic data are given in Tables 5 to 10. In contrast to the

chloride salt (MBCl.5H2O) the degree of hydration of the nitrate salt

(MBNO3.2H2O) is lower. The analytical data (Table 11) also

suggest the formula, C16H18N4SO3.2H2O(MB(NO32O).

The crystal structure is stabilized by pi-pi interaction between the

adjacent aromatic moieties stacked in antiparallel fashon along b axis at a

distance of 3.740(18) Aº as well as interlinking of the aromatic moieties by

hydrogen bonds. This interaction occurs pairwise (Fig. 9). The nitrate ion

and the water molecules form one-dimensional chain in a direction (Fig.

10). This is linked to the aromatic ring via C-H…O and NH…O

interactions. The adjacent stacked pair is stabilized by hydrogen bonding

interaction involving N(10) of the aromatic ring, nitrate and water

molecules (Fig. 11). These intermolecular interactions contribute to the

supramolecular structure of the product (Fig. 12).

Reaction of Mercury(II) Chloride with Methylene Blue

In the IR spectrum of Methylene Blue (Fig. 4) the .cs which occurs

at 1250 cm-1 is shifted to 1241 cm-1 in the product (2) (Fig. 13). This is

indicative of a reaction. From the IR spectral data it can be inferred that

coordination might have occurred through sulfur. The formulation of

(MB)2HgCl4 is also possible for the product. This is supported by the

analytical data (Table 11).

Reaction of Silver Nitrate with Lecuomethylene Blue:

In the IR spectrum of Methylene Blue (Fig. 4) the .CN stretching

frequency occurs at 1446 cm-1, which is significantly shifted to 1454 cm-1,

in the product (3) (Fig. 14). Similarly, the .C=C is shifted from 1599 cm-1 to

1642 cm-1. This shows that the reaction has occurred and the coordination

might have occurred through the N atom.

Reaction of Mercury(II) Chloride with Lecuomethylene Blue:

In the IR spectrum for the Methylene Blue (fig. 4) the .CN

stretching frequency occurs at 1446 cm-1, which is shifted to 1454 cm-

1 in the product. Similarly, the .C=C is shifted from 1599 cm-1 to 1634 cm-1

in the product (4) (Fig. 15). This shows that the reaction has occurred

between the two reagents and the coordination, if any, might have occurred

through the N atom.

The correct structures can be assigned using X-ray crystallographic

investigations. However, attempts to prepare crystals of products of the

reactions of Lecuomethylene Blue with mercury(II) chloride and silver

nitrate were not successful, although several attempts were made.

4013060801001204000400100020003000%TWavenumber[cm-1]

IR cm-1

: 3397, 1599, 1489, 1446, 1395, 1354, 1339, 1250,

1220, 1180, 1143, 1064, 1036, 947, 884, 854, 808, 666, 536,

Fig. 4. IR spectrum of Methylene Blue

4000.03000200015001000450.028.7354045505560657074.0cm-1%T

IR (cm-1): 3418, 1599, 1486, 1443, 1384, 1356, 252, 1176, 1147, 1082,

961, 884, 814, 612.

Fig. 5. IR spectrum of Methylene Blue Nitrate

Fig. 6. UV-Visible spectrum of Methylene Blue

Fig. 7. UV-Visible spectrum of Methylene Blue Nitrate.

Table 2: UV Spectral data for Methylene Blue and its ‘product’

with Silver Nitrate

UV/10mg/10ml

Diluted 400 times

Methylene Blue

.max (nm)

Methylene Blue

nitrate

.max (nm)

665

665

259

293

Table 3: Bond Lengths in Methylene Blue Derivatives4,5,6

Chloride Thiocyanate Acetone solvate

C(1)-C(2) 1.341 1.357 1.343

C(1)-C(11) 1.417 1.411 1.426

C(2)-C(3) 1.445 1.436 1.423

C(3)-N(3) 1.331 1.48 1.344

C(3)-C(4) 1.419 1.391 1.416

N(3)-C(32) 1.454 1.489 1.463

N(3)-C(31) 1.465 1.546 1.444

C(4)-C(12) 1.349 1.341 1.375

S(5)-C(13) 1.738 1.736 1.728

S(5)-C(12) 1.721 1.742 1.729

C(6)-C(13) 1.356 1.356 1.368

C(6)-C(7) 1.401 1.401 1.391

C(7)-N(7) 1.344 1.314 1.355

C(7)-C(8) 1.423 1.447 1.443

N(7)-C(71) 1.444 1.536 1.456

N(7)-C(72) 1.444 1.508 1.453

C(8)-C(9) 1.349 1.346 1.35

C(9)-C(14) 1.421 1.409 1.409

N(10)-C(11) 1.336 1.329 1.324

N(10)-C(14) 1.337 1.353 1.343

C(11)-C(12) 1.439 1.418 1.438

C(13)-C(14) 1.42 1.401 1.443