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Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 1
Coordination polymer &Polymer-metal
complexes: Synthesis, characterization, and
properties
____________________________________________________________________
By
Awad Nasser Al-Balawi
Department of Chemistry
King Saud University
December,2013
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 2
Contents
Subject Page
N0# Cover -
Contents 2
1-Introduction 1-1 polymer-metal complex
1-2 Classification of polymeric metal complexes
4-7
2- Synthesis of Coordination Polymers and polymer-metal complexes 2-1. Synthesis of Coordination Polymers 2-1-1Polymerization through pre-formed metal complexes 2-1-2Coordination of a metal ion by a pre-formed polymer containing chelating groups 2-1-3.Coordination reaction of a ligand, which can attach itself simultaneously to two metal atoms or ions 2-2- Synthesis of polymer-metal complexes: 2-2-1 Complexation polymeric ligand with metal ion 2-2-1-1 Pendant complexes 2-2-1-2 Inter and Intra molecular bridging 2-3-Polymerisation of monomeric metal complexes 2-4 Complication of bi functional ligands with metal ion Example.1-Synthesis and Characterization of Polymer Metal Complexes poly-[DHPF-M(II)Cl2] which is used as Catalytic Activity in Ethylene Oligomerization Example.2- Synthesis of polymer–copper(II) complex. Example.3- Synthesis of oligo-2-[4-iodophenylimino) methyl ] phenol-metal complexes Example.4-Synthesis of the monomers and four polymeric metal complexes (P1–P4).
5-22
4-Chemical Modification of polymer metal complexes Functionalised polymers and their metal complexes: Synthetic and characterisational aspects
23-30
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 3
Subject Page N0#
5-Physical and chemical properties of polymer metal complexes
5-1- XRD analysis:
5-2- Fourier transform-infrared spectroscopy (FT-IR) 5-3-Thermogravimetric Analysis.
5- 4-Electrical properties 5-5-Optical properties
5-6- Electrochemical properties 5-7-Elemental analysis: 5-8-Magnetic measurements
5-9- Thermal analyses 5-10-NMR spectroscopy
31-38
6-Applications of polymer metal complexes 6-1-Catalytic Activities of Polymer-metal Complexes 6-2-Mechanochemical Systems 6-3-Biologically Important Polymer-Metal Complexes 6-4- Biomedical applications (Anti-bacterial activity and Anti-fungal activity) 6-5- Polymeric Ligands in Metal Ion Separations 6-6-Solar Energy 6-7 Semi conductivity
39-44
Acknowledgment 45
References 46-50
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 4
1-Introduction Over the last several decades, polymer–metal complexes have gained increasing
scientific interest for their effectiveness in various fields .
Polymeric materials with the ability to create complexes with metal ions are very
common, originating from both natural and synthetic sources [1-2]. Recent progress
made in design and synthesis of novel coordination polymers has brought a variety of
polymeric materials that exhibit the structural diversities and attractive properties
which can be further utilized in various fields, like in catalysis [3-4], organic synthesis
[5], wastewater treatment, polymer drug graft, recovery of trace metal ions 6], and
antimicrobial activities [7,8 ]. , optics, luminescence and sensor technology [9] .
A polymer-metal complex is a coordination complex between a ligand functional
group anchored to a polymer matrix and a metal ion, in which the metal ion is
attached to the polymeric ligand by a coordinate bond. The synthesis of a polymer-
metal complex can take place by the synthesis of a macromolecular ligand followed
by the binding of the metal salts which involves different processes, such as
complexation, coordination, ion exchange and electrostatic attraction or by the
incorporation of a metal by polymerization of a suitable metal containing
monomer [10]
Voges et al . reported the free radical polymerization of vinyl monomers containing
transition-metal ions[11] . Tomono et al. [12] reported the radical polymerization of Cu-
complex with Schiff base ligand containing vinyl group . Free radical polymerization
of methacrylate monomers coordinated to Co (III) complexes was reported by Osada
et al . [13] . Kurimara et al . [14] prepared a series of pendant-type polymer-metal
complexes having a uniform structure by the substitution reaction between a polymer
ligand and a metal ion, such as Co (III) or Cr (III) . Dingman et al . [15] studied the
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 5
adsorption of metal ions on poly (ethyleneimine) crosslinkcd with toluene
diisocyanate and reported that the amount of metal ions adsorbed decreases with an
increase in the degree of crosslinking. Here the synthesis and characterization of poly
(2-hydroxy-4-acryloyloxy acetophenone formaldehyde) and its Cu (II) and Ni (II)
complexes, are reported.[16]
The free radical polymerization of Cu complexes with a Schiff’s base ligand
containing a vinyl group and the radical polymerization of methacrylate monomers
coordinated to Co(III) were studied by Kaliyappan et al. [6]. Polymers that contain
nitrogen as donor atoms were synthesized and used in the complexation of transition
metal cations [17]. Among these polymers,4-vinylpyridine (4-VP) is considered
strongly functional [18].
1-1-polymer-metal complex
A polymer-metal complex is a coordination complex between a ligand function
anchored on a polymer matrix and a metal ion in which the metal ion is attached to
the polymeric ligand by a coordinate bond. Here a polymeric ligand is considered as a
polymeric substance that contains coordinating groups or atoms mainly N,O and S.
The polymeric ligand can be obtained by the polymerization of monomers containing
coordinating sites or by the reaction between a polymer and a low-molecular weight
compound having coordinating ability. 1n a polymer-metal complex, a complex with
a specific structure results since the metal ion is surrounded by a structured polymer
chain. Polymer-metal complexes show unique properties which are distinctly different
from their low- molecular weight analogues. These unique properties originate from
the properties of the polymer backbone.
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 6
1-2-Classification of polymeric metal complexes
The polymeric metal complexes are classified into the following groups:
(A) polymer-metal complexes
(B) coordinate polymers
(C) poly(metal-phthalocyanine) type
Polymer-metal complexes, represented by Schemes 1 to 5, are defined as complexes
composed of a polymer ligand and metal ions in which the metal ions are attached to
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 7
the polymer ligand by a coordinate bond. Here a polymer ligand is understood to be a
polymeric substance that contains coordinating groups or atoms (mainly N, O, and S),
obtained by the polymerization of monomers containing coordinating sites, or by the
chemical reaction between a polymer and a low-molecular- weight compound having
coordinating ability Typical polymer ligands previously reported are listed in Table I.
When a polymer ligand is mixed directly with a metal ion, which generally has four or
six coordinate bonding hands, a polymer-metal complex is formed. This may be of the
intra-polymer chelate type (Scheme 1) or of the inter-polymer chelate type (Scheme
2). Complex formation proceeds via Scheme 3, where the polymer backbone contains
multidentate ligands, such as the iminodiacetic acid group, or acts as a carrier for low-
molecular-weight mu!tidentate ligands; many so-called chelating resins fit this
scheme. The polymer-metal complexes represented by Schemes 1 to 3 have chelating
structures in their polymer ligands and are therefore called polymer chelates. The
pendant-type polymer-metal complex (Scheme 4) is formed by the reaction of a
polymer ligand with a stable metal complex, the central metal ion of which has
already been masked with lowmolecular- weight ligands except for one coordinate
site that remains vacant, e.g. metalloporphyrins, or cobaltic chelates. A polymer-metal
complex is also obtained by polymerizing a monomeric metal complex (Scheme 5).
Scheme 6 represents coordinate polymers. A low.molecular-weight compound with
multidentate groups on both ends of the molecule grows into a linear polymer with
metal ions, and the polymer chain is composed of coordinate bonds. The parquet like
polymer complexes, poly(metal-phthalocyanine) and poly(metal-tetracyanoethylene),
are classified into Scheme 7. They are formed by inserting metal ions into planar-
network polymers or by causing a low.molecular-weight ligand derivative to react
with a metal salt and a condensation reagent.
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 8
2- Synthesis of Coordination Polymers and polymer-metal complexes
2-1. Synthesis of Coordination Polymers
The literature reveals three possible methods of preparing metal coordination
polymers (Marcos, 1992)[20] .
The first method involves polymerization through pre-formed metal complexes
through functional groups where the polymer forming step is typically a condensation
or an addition reaction. The second method includes the coordination of a metal ion
by a preformed polymer containing chelating groups. In the third method, a metal
coordination polymer is formed by a coordination reaction of a ligand, which can
attach itself simultaneously to two metal atoms or ions (Ismet, 2008).[21]
In theory and in practice, a myriad of ligands can be employed for such procedures.
This can be seen as a means through which various architectures can be produced
covering a wide circle of many metal atoms and ions. Some typical ligands are
displayed in table 1.
Table 1: Some ligand groups with examples, typically used in the synthesis of metal
containing polymers (Batten et al., 2008)[22 ].
Ligands bind metal atoms mainly through nitrogen or oxygen where the binding
modes affect the conformation of the metal containing polymers. Figure 1 shows a
number of binding functional groups through which the ligands bond the central metal
atoms or ions.
Ligand class Example(s)
Amides 4-(methylamino)benzoic acid
Carboxylate based Acetate, Carboxylate
Nitrile based Nitrile based 1,3,5-tris(4-ethynylbenzonitrile) benzene, 1,3,5-tris(3-
Pseudohalide Cyanide, Azide
Sulfonate containing 4-sulfo-benzoate, , naphthalene-1,5-disulfonate
5 membered heterocyclic Pyrazole, Triazole
6 membered heterocyclic Pyrazine, Piperazine, Pyrimidine
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 9
1- Polymerization through pre-formed metal complexes
In this concept, a metal complex is prepared from the reaction of a ligand with a metal
ion. The prepared metal complex is then polymerized through the various
polymerization reaction mechanisms. This is as reported by Irina (2008)[23], on the
synthesis and electro optical properties of metal-containing azopolymers and the
influence of steric factors on the electro-optical effect in poly complexes of
azobenzene derivatives with Cobalt. The synthesis was achieved by first, synthesizing
the azo compounds 4-hydroxy-(4’-carboxy-30-hydroxy)-azobenzene and 4-hydroxy-
(2’-carboxy)-azobenzene. The synthetic route for the target monomers is shown by
schemes 9 and 10. Complexes of 4-methacroyloxy-(40-carboxy-30-hydroxy)-
azobenzene and 4-methacroyloxy-(20-carboxy)-azobenzene with Cobalt were
synthesized by the exchange reaction between acetates of the corresponding metal and
monomers. The polymers were finally obtained by free-radical polymerization with
AIBN as free radical initiator. The polymers show photoinduced optical anisotropy
which is as a result of irradiation by linearly polarized light, which causes trans-cis
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 10
isomerization of azobenzene groups. There was an orientation of the light-induced
dipole moments of these groups by an external electric field, causing the electro-optic
effect at wavelengths near the long-wave absorption edge of the polymers.
Scheme 9: Synthesis of 4-methacroyloxy-(40-carboxy-30-hydroxy)-azobenzene
Scheme 10: Synthesis of 4-methacroyloxy-(20-carboxy)-azobenzene[52]
Shagisultanova (1996)[24] reported the synthesis and properties of photoactive and
electroactive polymers based on transition metal complexes. Electrochemical
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 11
reduction of iron, ruthenium and osmium complexes containing 5-Cl- Phen as ligand
leads to the growth of metallopolymers on the metal surface. The polymers were
found to be very stable to repeated electrochemical cycling and were highly
reproducible.
2- Coordination of a metal ion by a pre-formed polymer containing chelating
groups
In this aspect, a polymer is formed by any of the conventional polymerization
mechanisms. The pre-formed polymer, containing chelating groups is then
coordinated to the metal ion. This was demonstrated by Weilin et al (2003)[25] who
worked on the synthesis and ferromagnetic property of Bithiazole based polymer and
its ferro complex containing hexacyanoferrate (III) group.
The polymer (referred to as SDP) was prepared according to the reaction scheme 3.
The precipitate thus produced was collected by suction filtration, followed by washing
successively with water, methanol, and ether and dried in vacuo at 60◦C for 24hrs to
give a yellowish-green powder (yield 90%). Ferro-Complex (SDP-Fe2+) was prepared
from the reaction of SDP and FeSO4 in DMSO for 5 days at room temperature under
a purified nitrogen atmosphere. SDP-Prussian blue complex was prepared from
reaction of K3[Fe(CN)6] in DMSO with SDP-Fe2+ complex and the resulting
suspension was allowed to react for 3 days at room temperature. Elemental analysis
yields the formula [C15H12N4O3S2 (FeSO4) 0.23]n and
{C15H12N4O3S2[KFeFe(CN)6]0.20}n for both complexes. The presence of
ferromagnetic coupling between iron ions through cyano bridging linkage in SDP-
Prussian blue is proposed based on the electron spin resonance spectroscopy (ESR).
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 12
Scheme 3: Synthetic route of SDP, SDP-Fe2+ and SDP-Prussian blue and suggested structures.
Vaishali (2006) reported the Preparation, characterization, magnetic and thermal
studies of some chelate polymers of first series transition metal ions. A modified
method (Priyadarshini and Tandon, 1967)[49] based on Schotten Baumann reaction
was used for the preparation of hydroxamic acid (Ukey, 2006)[50]. The chelate
polymers were prepared according to the procedure described by (Ukey, 2006)[60].
Figure 12 shows the proposed structure of the chelate polymers. On the basis of
elemental analyses, infrared (IR) spectra, reflectance spectra, magnetic moment data
and thermal studies, the [Zn(II)(ABHA)]n chelate polymers have tetrahedral
Fig 11
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 13
geometry, whereas [Mn(II)(ABHA)(H2O)2]n, {[Ni(II)(ABHA)-(H2O)2]·(H2O)}n and
{[Co(II)(ABHA)(H2O)2]·(H2O)}n chelate polymers have octahedral geometry and
order of reactions has been found to be approximately one and have thermal stability
in the order Ni(II) > Mn(II) > Zn(II) > Co(II).
Figure 2: Proposed structure of the chelate polymers of azelaoyl-bis-hydroxamic acid,
where *H2O-water of hydration and H2O-water of coordination. M= metal ion,
Mn(II), Co(II), Ni(II) and Zn(II). *H2O is absent in case of Mn(II) ABHA chelate.
Both H2O and *H2O molecules are absent in the case of Zn(II) ABHA chelate
polymer.
3- Coordination reaction of a ligand, which can attach itself simultaneously
to two metal atoms or ions.
Coordination polymers and oligomers containing dimetal clusters have not been
explored as much as other coordination polymers, although numerous bridgded
dimetal units containing copper, rhodium, molybdenum and ruthenium are known
Fig12
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 14
(Craig, 2002)[51] and recently, two reviews describing examples of dimetal
tetracarboxylate unit containing one-dimensional polymers appeared (Craig, 2002)[51]
211]. Tetrakis(carboxylato) rhodium compounds were first reported in 1960. The
preparation of the polymers was achieved by the use of metal containing building
block with free donor sites which can be joined together through the free binding sites
to form many repeating units (polymers).
Reported by Craig (2002)[51] is the synthesis of a new mixed-metal Mn–Rh
coordination polymer assembled from Mncontaining molecular building blocks and
Rh2(OAc)4 dimers. The starting material Mn(2-methylpyrazine-5-
carboxylato)2(H2O)2, was synthesized by reacting 2-methylpyrazine-5-carboxylic
acid with MnCl2- 6H2O in a basic solution. It was then reacted further with
Rh2(OAc)4 by layering the two reactants in methanol and ethanol, respectively which
yielded small red block crystals. Single crystal X-ray diffraction revealed the red
crystals to be a new mixed-metal manganese/rhodium coordination polymer
{[Mn(MePyzca)2(MeOH)2][Rh2(OAc)4]} 2MeOH. This new manganese–rhodium
mixed metal coordination polymer complements other known systems based on the 2-
pyrazinecarboxylate and 2-methylpyrazine-5-carboxylate ligands. In all cases, the
ligand chelates one metal center with a carboxylate oxygen and one nitrogen donor
while using the para nitrogens to bind a second metal.[52]
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 15
Fig.13
Fig.14
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 16
2-2- Synthesis of polymer-metal complexes:
2-2-1 Complexation polymeric ligand with metal ion
This type of complex formation is achieved by mixing a polymer containing
ligand functions like amine, ketone, dithiocarbamate, carboxyljc acid, thiol, schiff
base . with metal Ion or metal complex solution. The reaction usually resulted in
various types of co-ordination structures like pendant, inter and intramolecular
bridged complexes.( Chacko - 2010 )[20]
2-2-1-1 Pendant complexes
a metal ion or metal complex has only one labile ligand which is easily substituted
by a polymeric ligand and when other co-ordination sites are substituted by a
polymeric ligands and other coordination sites are substitution inactive. a
amonodentate pendant complex is formed.
The polymer complex cis [Co(en)zPVP.CI]C12 was prepared by mixing an
ethanolic solution of PVP with an aqueous solution of Co(1ll) chelates and heating
at 80°C for 2-6 h. The solution was filtered and the filtrate was dialysed in cold
water. After the water was evaporated thin films of reddish violet PVP complex
was obtained.
A polymeric ligand having polydentate structure will form polydentate
pendant complexes.
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 17
2-2-1-2 Inter and Intra molecular bridging
The reaction of a polymer ligand with metal ions very often results in inter and /or
intramolecular bridging.
2-2-Polymerisation of monomric metal complexes
If a monomeric metal complex containing a vinyl group is polymerized without
side reaction, a polymer metal complex having uniform structure is obtained.
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 18
Typical example of the polymerization of a vinyl monomer containing translation
metal ion is the radical polymerization of vinyl ferrocene. Vinyl t'errocene and its
derivatives are polyrmerised by a radical or cationic initiator to atom a polymer of
high molecular weight. Methacrylate monomer coordinated to Co(III) complex eg.
methacrylate pentamine Co(III) perchlorate was radically perchlorate was radically
polymerised get the polymer metal complex. (Chacko - 2010) [20]
Complication of bi functional ligands with metal ion
When bifunctional ligands form a complex with metal Ions having more
than two labile ligands which are easy to be substituted a polymer complex IS
formed through metal Ion bridging . this type of polymer metal complex has been
used as semiconducting organic materials, heat resistant organic copolymers or
polymer catalysts .
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 19
Example.1-Synthesis and Characterization of Polymer Metal Complexes poly-
[DHPF-M(II)Cl2] which is used as Catalytic Activity in Ethylene
Oligomerization
Ahamad and ALshehri 2013, reported a new polymeric ligand, 4,7-dihydroxy-1,10-
phenanthroline/formaldehyde polymeric ligand [poly-(DHPF)], which was
synthesized via the polycondensation of 4,7-dihydroxy-1,10-phenanthroline and
formaldehyde in an acidic medium. Polymer metal complexes, poly-[DHPF-
M(II)Cl2], were subsequently prepared with Co(II) and Ni(II) ions. Poly-(DHPF) was
prepared through the condensation polymerization of formaldehyde and 4,7-
dihydroxy-1,10- phenanthroline in an acidic medium. Polymer metal complexes were
prepared upon the reaction with metal salts, using a 1:1 molar ratio of polymeric
ligand to metal. The synthetic routes for both the polymeric ligand and its polymer
metal complexes are given in Scheme 15. The poly-([DHPF-Co(II)Cl2]) was isolated
as a blue powder, whereas poly-([DHPF-Ni(II)Cl2]) was green. Slight deviations in
the elemental analysis may be due to the polymeric nature of the compounds, as the
values for the end groups are not taken into account for the theoretical calculation. [21]
Scheme15
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 20
Example.2- Synthesis of polymer–copper(II) complex.
Cao et al 2013 & Tsuchida et al 1977 reported method for Synthesis of polymer–
copper(II) complex (fig). the water-insoluble polymer–copper(II) complex was
synthesized in supercritical carbon dioxide by using methanol as a cosolvent and N,N-
methylenebisacrylamide as a cross-linker. In a normal reaction, three basic steps are
performed to synthesize the polymer–copper (II) complex. First, copper sulfate and
4-VP are used as the coordination ion and the functional monomer, respectively,
Second, a free-radical initiator (AIBN), a cross-linker (BISl), and an appropriate
is then immediately 2the autoclave. CO amount of methanol are loaded into
introduced . Third, the system is isolated, and the autoclave is placed in a water bath.
In addition, the reagents are mixed and dissolved before heating the reaction system to
]22,23[.( scheme16) temperaturethe reaction
Scheme.16
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 21
Example.3- Synthesis of oligo-2-[4-iodophenylimino) methyl ] phenol-metal
complexes
Kaya & Baycan 2007 reported synthesis Polymer–metal complex compounds were
synthesized from the reactions of poly-2-[(4-mercaptophenyl) imino methyl] phenol
(P-4-MPIMP) with Cr3+, Co2+, Ni2+, Cu2+, Mn2+, Zn2+, Pb2+, Cd2+ and Zr4+ ions.[25]
Oligomer-metal complexes were synthesized from the reactions of OIPIMP(2-[(4-
iodophenylimino)methyl]phenol with Co(II), Ni(II) and Cu(II) acetates. As shown in
the Scheme 18.
Scheme17
Scheme.18
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 22
Example.4-Synthesis of the monomers and four polymeric metal complexes (P1–P4).
Jin et al2013 reported Four main chain polymeric metal complexes (P1–P4) based on
1,10-phenanthroline metal complexes via the Heck coupling have been synthesized
Schem.19. [26]
Scheme 19. Synthesis of the monomers and four polymeric metal complexes (P1–P4).
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 23
4-Chemical Modification of polymer metal complexes
4-1-Functionalised polymers and their metal complexes: Synthetic and
characterisational aspects
In 1963, Merrifield introduced the concept of solid phase peptide synthesis,
after which solid polymer supports were used extensively in other areas of
chemistry ' The advantages of solid phase reactions are the operational simplicity,
possibility of using one of the reagents in excess, and the ease of purification.
Polymer supports have gained wide application not only in solid phase peptide'
synthesis but also in different areas like immobilisation of enzymes, biomolecules,
catalysts, reagents and in metal ions separation.
The polymer support should be functionalised before exploiting them for chemical
processes like peptide synthesis, catalysis, chelation or metal ion separation.
Functionalisation involves the incorporation of a functional group to the polymer
support.
Chloromethyl polystyrene crosslinked with 1-2% divinyl benzene is the
most commonly used support. Functionalisation of styrene polymers primarily
involves electrophilic substitution on the aromatic ring. Chloromethylation has
been the most widely used reaction. Chloromethylation of styrene polymers is
carried out using a Lewls acid catalyst and chloromethyl methyl ether as the solvent.
In addition to their direct use, chloromethyl groups can be readily modified into
other functional groups Different functional groups may be directly introduced
into the polystyrene support by well known reaction sequences .
Several ligand functions were anchored to polymer support by polymer
analogous reactions to get polymer supported ligands. These polymer supported
complexing agents find wide application in various fields.
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 24
a- incorporation of ligand,
Two approaches exist for the preparation of functional polymers, namely the
polymerization or copolymerization of monomers which carry the desired
functionality and the chemical modification of the preformed polymer. The
tormer is the more direct approach and many functional linear polymers can be
prepared without difficulty by free radical, anionic, cationic, co-ordination or
group transfer polymerization . However for most purposes cross-linked polymers
are more attractive than linear polymers. The preparation of crosslinked polymers
in a good physical form is most readily achieved by suspension polymerization.
The alternative to direct copolymerization for the preparation of functionalized
polymers is the chemical modification of preformed polymers.
'This method is preferred to others in view of the fact that the degree of
functionalisation can be controlled by varying the amount of crosslinking agents
and the extent of modification in preformed matrices. The method involving
copolymerization of monomers controlling the desired functionality's widely used
to produce Ion exchange and complexings sorbents.
Vinyl monomers are usually used and the synthesis involves the polymerization of &
of vinyl compounds containing chelating groups like pyridine, 8-hydroxyquinoline,
Imidazole carboxylic acid etc. with divinyl compound .Yeh et al . reported the
Preparation of polystyrene based acetyl acetone by direct emulsion polymerization
of a vinyl benzyl acetyl acetone with styrene using the conventional emulsion
system or by bulk polymerization using azobisisobutyronitrile as solvent and by
irradiating the monomer by UV radiation. This method of synthesis makes it
possible to obtain sorbents of high capacity and a uniform structure of the polymer.
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 25
Chemical modification of the preformed polymer is the easiest method for the
Synthesis of wide variety of macromolecular ligand systems. This method is
generally used for the functionalisation of a polymer matrix. The required ligand
function is Introduced on to the polymer matrix by simple polymer analogous
organic reactions Imdazole supported on styrene divinyl benzene copolymers can
be prepared from chloromethylated styrene DVB copolymers and the sodium or
lithlum salts of imazoluesing dimethyl form amide or tetrahydrofuran as
solvent . the bidentate ligand 2,2'-bipyridine has successfully incorporated into
polystyrene by (Card and Neckers' according to Scheme.20below
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 26
Drago et al. described the strategy for covalently attaching multidentate chelating
ligands to polystyrene matrix. Polymeric substrates containing polydentate amines can
be obtained by reacting chloro or iodomethyiated polystyrene with bis
(cyanoethylamine) followed by BF,-THF reduction. Preparation of polymer attached
bis(3-aminopropyl) mine is depicted in Scheme.21 below.
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 27
Bhadurl and Khwaja synthesized some polymer supported dithiocarbamate ligand
from chloromethylated styrene divinyl benzene copolymers (8%) using the sequence
of reactions given below scheme.22.
Polycondensation is another important method for synthesizing polymers
bearing chelating ligands. This method involves the copolymerization of certain
21
22
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 28
ligand molecule with phenols and aldehydes. For example, anthranilic acid,
; anthranihc acid diacetic acid,. m-phenylene diamine can be copolymerised with
formaldehyde and mono or polyphenols to synthesize condensation chelating
polymers. Unicellex UR-50 is a chelating Ion exchange resin prepared by the
copolymerization of N-(0-hydroxybennl) imidodiacetic acid with phenol and
formaldehyde. Recently Patel et a1 prepared a polymer by condensation of 2-hydroxy
4-methoxy acetophenone and 1.4-butane diol.
The two-stage metallation of the polymer by chelate complexes of butyllithium with
subsequent functionalization of metal-containing intermediates has been employed
successfully for modification of a number of polymers, for example, polystyrene,
cis-1,4-polybutadiene,and cis -1,4-polyisoprene. Earlier, an attempt was made to
apply the same approach for functionalization of PTMSP with the use of normal
butyllithium in a polar medium and a hydrocarbon medium containing electron-donor
additives. However, the degree of metallation of the polymer by the above systems
turned out to be low. As a result, only a small amount of functional groups (not
greater than 8 mol % even when a threefold excess of the metallating agent was used)
was incorporated into PTMSP.
(Scheme (23))The metallation of PVTMS and PTMSP was performed with the use of two types of
metallating agents—normal and secondary BuLi—as chelate complexes with TMEDA.
Chirkova et al 2006 reported that Poly(vinyltrimethylsilane) and poly(1-
trimethylsilyl-1-propyne) are metallated using normal and secondary butyllithium
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 29
chelate complexes with tetramethylethylenediamine and superbases based on
complexes of normal and secondary butyllithium with potassium tert -pentoxide as
metallating agents. Poly(vinyltrimethylsilane) and poly(1-trimethylsilyl- 1-propyne)
are functionalized via reactions of metallated polymers with CO2 , trimethylsilyl
chlorosulfone, diethyl disulfide, and ethylene oxide. COOH, SO3H, OH, and thioester
groups are introduced into poly(vinyltrimethylsilane), and SO3H and COOH groups
are incorporated into poly(1-trimethylsilyl-1-propyne). Upon introduction of carboxyl
groups into poly(vinyltrimethylsilane), its hydrophilicity and permselectivity with
respect to H2O/N2, H2O/H2, and H2O/CH4 pairs increase. The introduction of SO3H
groups into poly(1-trimethylsilyl-1-propyne) and poly(vinyltrimethylsilane) leads to
the appearance of proton conductivity of these polymers.( Chirkova et al 2006)[27]
It was reported that Fullerenes, in particular C60 as one of the new materials - has
been bonded to polymer-metal complex for the first time with two methods. C60 is
directly coordinated in the side-group attached to the main chains of polymer to form
PVPy (charm Bracelt)-metal (Cu, Co, Ni ...)-C60 complex or it is, in a
anion,coordinated with the polymers. To gain Pearl Nechleace polymer, some
diamino derivatives of C60 have been synthesized. The complex with C60 can be
coated on some substrates, such as silicon, glass, alumina (AI2O3), to form the film.
The polymer-metal-C60 complex (P-M-C60) can be implanted by H+, P+,B+ , Sb+ or
metal ions to modify the complex.( Zhang et al 1995)[28]
Shunmugam, & Tew 2008 stated that the area has begun to focus considerable effort
on the properties of these materials for various applications that will move the field
from interesting molecules to ‘functional materials,’ a very promising prospect.
Nevertheless, the ability to engineer functional materials rests on the availability of
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 30
novel materials and, therefore, on advances in synthetic chemistry. Figure .24below
shows a selected summary of various structures reported to date in this area with a
focus on those used for emission properties .[29]
Scheme24
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 31
5-Physical and chemical properties of polymer metal complexes
Analysis and Characterization of Polymer-Metal Complexes
Usual chemical methods of analysis applied to low-molecular weight species have
been found to be satisfactory with linear polymers. But with crosslinked
polymers such methods which require solubilization of the samples cannot be applied.
The detection and estimation of the elements present in the polymer-complexes are
carried out by elemental analysis. The different functional groups (ligands) are
detected qualitatively by the general chemical tests and from their typical IR
absorptions. If the ligand functions supported on the polymer are acidic or basic, a
quantitative estimation of the groups can be done by titrimetric method, provided,
the support material allows penetration of the aqueous reagents. In the case of
reagents where the penetration of the aqueous reagen,ts is difficult, it is better to
react the supported group with excess of acid or base, allowing the reaction for a
sufficiently long period and then to carry out back titration. The complexed metal
ions are estimated by volumetric, spectrophotometric or gravimetric methods. The
metal ion intake is usually expressed as milligram of. metal ion complexed by one
gram of the resin.
The coordination of a polymeric ligand to metal ion and the structures of the resulting
polymer metal complexes are studied spectroscopically and by measuring the
magnetic properties. Infra-red (IR), visible, electron spin resonance(ESR), NMR,
Scanning electron microscopy(~M), X-ray, optical rotatory dispersion(ORD) and
circular dichroism(CD) can be made use of for the structure elucidation of polymer-
metal complexes.
Thermal studies (TGA/DTA) have also been used to explore composition, structure
and thermal stabilities of polymeric ligands and their metal complexes. Applications
of these methods are illustrated in the respective sections dealing with individual
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 32
chelating polymers and their metal complexes. Increasing importance is not
attached to the use of these methods as various physical measurements can help in
adequate characterization of crosslinked chelating resins to indicate the chemical
environment of the attached chelating group.
Physical and chemical properties of polymer metal complexes Can be
Characterization by several techniques as following:
5-1- XRD analysis:
The crystallinity of the polymer–metal complex often is examined by powder XRD
For example , it can explain the XRD analysis for the synthesis of Example.2-
Synthesis of polymer–copper(II) complex. Cao et al 2013 explain the fig.2 saying
that the curves indication to (a) the polymer and (b) the polymer–copper(II)
complex. the fig.25 show that there is no Cu peaks are observed in the diffractograms
of the polymer complexes of 4-VP. This result indicates that these complexes are not
composed of single crystallites . This result also indicates the absence of excess salt in
the complexed polymer. The XRD patterns of samples (a), polymer (b), and the
polymer–copper(II) complex are similar. However, the intensity of the peaks
increases after the monomer interacted with the copper ions. This behavior indicates
that the complexation between copper(II) and the polymer link, which takes place in
metal –e polymerthe polymeric network, results in an amorphous structure of th
]22, 29[complex.
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 33
Fig. 25. XRD analysis of (a) the polymer and (b) the polymer–copper(II) complex.
5-2- Fourier transform-infrared spectroscopy (FT-IR)
The FT-IR spectra of the compounds ( monitor , polymer, polymer- metal
compolexes ) can be recorded as KBr discs using FT-IR spectrophotometer .
Absorption frequencies are given in wave numbers (cm−1). FTIR bands and its
signals of monomer, its polymer-metal complexes with their assignments are can be
observed . It give indication on the present/ formation the Metal- function group
bond and other function group, in the polymer- metal complexes.
The formation of polymer metal complexes can be followed from their
characteristic absorption bands in infra-red and far infra- red spectra and comparing
them with the corresponding low molecular weight complexes. The IR absorptions
by a ligand are usually shifted by complex formation with metal ions. The
absorption band at 1600 cm-1 of (C=C) or (C=N) of poly(4-vinyl pyndine), (PVP)
shifts to a higher wave number by about 20 cm-1 in cis [CO(en)2 PVP.CL]CL2
cis[Co(trien)PVPC]CL the (C=C) and (CH) of PVP also shift to higher wave
number in the Co(I1I) complex. When two kinds of ligands capable of coordination
are present in the polymer, the IR spectra can be used to find out the group which
participates in co-ordination .( Chacko - 2010 )[20]
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 34
5-3-Thermogravimetric Analysis.
The thermal decomposition of polymer , and its polymer metal complex can be
studied by the thermogravimetric method. The thermogravimetric curves of polymer
and its polymer metal complex give indication on starting decomposing with weight
loss at certain temperature as a result in some cases of related to the volatilization
of both water and plasticizer . For example , it can explain the Thermogravimetric
Analysis related to the synthesis of Example.2- Synthesis of polymer–copper(II)
complex. Cao et al 2013 explain fig.3 saying that The TGA curves of cross-linked
P(4-VP) (a) and of the polymer–copper(II) complex (b) are shown in Fig. 26. The
starting volatilization temperature of the polymer complexes was about 315 ◦C, which
indicates that the polymer complexes are less stable than the PVP homopolymer.the
decomposition temperature of the cross-linked P(4-VP) is at 374 ◦C, whereinthe
polymer–copper(II) complex separated into two segments,
namely, at 315 ◦C and 515 ◦C.
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 35
5- 4-Electrical properties Electrical properties of doped and undoped polymer and polymer–metal complex
compounds can be determined by four point probe technique at room temperature
and atmospheric pressure using conductivity instrument . The pellets are pressed on
hydraulic press developing up to 1687.2 kg/cm2. Iodine doping is carried out by
exposure of the pellets to iodine vapor at atmospheric pressure and room temperature
in a desiccator , This discretion is according to reports by ( Diaz et al 1999 , Kaya &
Baycan. 2007) [30,24]
5-5-Optical properties
The optical band gaps (Eg) of monomer, polymer and its polymer–metal complex
compounds can be calculated from their absorption edges. Ultraviolet–visible (UV–
vis) spectra can be measured by (UV–vis) instrument . The absorption spectra of
monomer, polymer and polymer–metal complexes can be recorded by using methanol
Fig.26
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 36
and DMSO, respectively, at 25 ◦C . this method reported by (Wanger et al 2002)[31].
5-6- Electrochemical properties:
Cyclic voltammetry (CV) measurements usually carriy out with Electrochemical
Analyzer Instruments, at a potential scan rate of 20 mV/s. All the experiments are
performed in dry box under Ar atmosphere at room temperature. The electrochemical
potential of Ag is calibrated with respect to the ferrocene/ferrocenium (Fc/Fc+)
couple. The half-wave potential (E1/2) of (Fc/Fc+) is measured in 0.1 mol/L
tetrabutylammonium hexafluorophosphate (TBAPF6) acetonitrile solution is 0.39V
versus Ag wire or 0.38V versus saturated calomel electrolyte (SCE). The
voltammetric measurements are carried out for monomer, polymer and polymer–
metal complexes in acetonitrile and DMSO, respectively. The HOMO and LUMO
energy levels of the polymer and polymer–metal complexes are determined from the
onset potentials of the n-doping (φn ) and p-doping (φp), respectively, this method
was used for 4-MPIMP and P-4-MPIMP which reported by (Colladet etal 2004 & Li
et al 1999) [32,33].
It was reported The highest occupied molecular orbital (HOMO) and lowest
unoccupied molecular orbital (LUMO) energy levels of the polymer metal complexes
, which are crucial property for materials used , can be estimated by cyclic
voltammogram (CV). When saturated calomel electrode electrode was used as the
reference electrode, the HOMO, LUMO, and energy gap (Eg) can be calculated
according to Equations (1), (2), and (3), respectively, following the literature.[34]
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 37
5-7-Elemental analysis:
Carbon, hydrogen, nitrogen and sulfur contents often performe via elemental analyzer
.Analysis of metal ions after the dissolution of the solid complex in hot concentrated
nitric acid, HNO3, then diluting with distilled water and filtering to remove the
precipitated polymer ligand. The solution then is neutralized with ammonia solution
and the metal ions are then titrated with EDTA ,this method reported by(Vogel, 1978;
West, 1969).[35,36]
5-8-Magnetic measurements:
Magnetic susceptibilities of the complexes were measured by the Gouy method at
room temperature using a magnetic susceptibility balance .. Effective magnetic
moments were calculated from the expression µeff = 2.828 (XMT)1/2 B.M., where XM is
the molar susceptibility corrected using Pascal’s constants for the diamagnetism of all
atoms in the compounds and T is the absolute temperature (Mabbs & Machin,
1973).[37]
5-9- Thermal analyses :
The thermal degradations of monomer ,polymer polymer – metal complexes can be
studied by TGA– DTG–DTA analyses at N2 medium and thermal analyses results and
the curves of these analyses can be given as curves . such higher resistance against
high temperature of monomer and polymer and polymer metal complexes can be
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 38
explained base on the formation bonds between atoms. For example , high of thermal
stability of polymer–metal complex compounds may be indicate the formation of
metal–oxygen and metal–nitrogen coordination bond between polymer–metal ions.
The presence of water can be seen in TGA and DTG curves of polymer–metal
complex compounds . method of detecting glass transition temperatures can be
recorded by DTA and DSC . this method reported by (Cazacu et al 2004)[38]
5-10-NMR spectroscopy
NMR spectroscopy has also been used to study polymeric compounds 1H 13C and I9F
NMR spectroscopy were used In monitoring solid phase reactions 13C NMR
spectroscopy is used nowadays as a powerful spectroscopic method for the study of
cross-linked polymers .
The 1H NMR spectra for poly-ligand further support the characterization, as shown in
Evidence for the polymerization monomer and also give indications for
disappearance of the signals assigned to the cirtain protons. Coordination to the metal
ions is indicated by the expected upfield shifts (1H NMR) for the signals of protons.
In the 13C NMR spectra of poly and poly-Metal can be studied , for example . the
appearance of resonance signals for the CH2 groups & other group ( C-OH CH= N)
can a strong evidence for the presence of these groups in polymeric ligand and metal
complex,
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 39
6-Applications of polymer metal complexes
The study of the polymer-metal complexes has received increased interest recently in
various branches of chemistry, chemical technology and biology and the subject has
been reviewed. periodically The chelating polymers find application in collecting
transition metal ions as well as alkali and alkaline earth metal ion preconcentration
and recovery of trace metal ions , organic synthesis ', nuclear chemistry, water- and
waste water-treatment , pollution control, industrial processes , hydrometallurgy and
polymer drug grafts . In addition , polymer-metal complexes are also used as
mechanochemical systems and as models of bioinorganic systems
6-1-Catalytic Activities of Polymer-metal Complexes
Catalytically active polymers can be obtained by introducing a catalytic centre to a
polymer backbone and it is reasonable to assume that the catalyst bound to the
polymer will show specific catalytic activity, reflecting the properties of polymer
chain. In the case of metalloenzyme such as oxidase and haemoglobin where a metal
complex is the active site, the macromolecular protein is that which plays a significant
role. Polymeric catalyst reduces the possibility of catalyst poisoning since the atalytic
site is somehow protected by the polymer matrix. In a polymer-metal complex,
aggregation is physically prevented by the rigidity of the polymer matrix and has the
advantage of maintaining its catalytic activity over a wide range of concentration. In
polymer-metal complexes, the selectivity arises from the steric hindrance and/or
chemical environment of the polymer matrix." Polymer-metal complexes are
markedly useful as immobilised catalyst for practical use because it is more reactive
than the corresponding monomer analogous due to the specificities of their large
ligand molecules. It is mainly used in oxidations, hydrogenation hydrolysis,
hydrformylation , decomposion of H2O2, " initiation of radical polymerisation,
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 40
asymmetric synthesis and optical resolution.
There are only a few examples where such polymer metal complexes act as catalysts,
which include epoxidation, hydrosilylation, hydroformylation, and hydrolysis. A vast
number of N-heterocyclic organometallic compounds have been applied toward the
polymerization of ethylene owing to their low cost, low toxicity, and abundance,
rendering them versatile precursors. It was reported of synthesis of a 4,7-
dihydroxy-1,10-phenanthroline/formaldehyde polymeric ligand [poly-(DHPF] in an
acidic medium and its subsequent Co(II) and Ni(II) polymer complexes, poly-
([DHPF-Co(II)Cl2] and poly-([DHPF-Ni(II)Cl2]), respectively. In addition ,their
catalytic activities have been assessed under a range of conditions toward ethylene
oligomerization. (Ahamad and Alshehri 2013)[39]
6-2-Mechanochemical Systems
mechanochemical system is one which can convert chemical energy into mechanical
change which results in the deformation of the materials. A polyelectrolyte or a
polymer-metal complex acts as a sensor in a mechanochemical system. The addition
of Cu(II) ions to the filaments of poly(viny1 alcohol) dipped in an aqueous solution
caused a shrinkage of filamentsg5. The film is extended by about 20% on the
reduction of Cu(II) to Cu(I) and shrinks back to its original state on the oxidation of
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 41
Cu(1) to Cu(I1). The poly(viny1 alcohol) chain is densely crosslinked by the
extremely stable Cu(II) chelate but is loosened when Cu(II) forms the unstable CU(I)
chelate.
Mechanism of Mechanochemical change of PVA Filament Induced by Redox
Reaction of Ions
The viscosity of an aqueous solution of poly(viny1 amine) in the presence of Cu(II),
Ni(II) or Zn(I1) ions was sharply changed by changing the pH of the solution due to
the conformational change of the polymer The mechanochemical behaviour caused by
pH change is less than the change caused by the redox reaction of the complexed
metal ions .
6-3-Biologically Important Polymer-Metal Complexes
Metal ions have an important role in the activity of bioinorganic materials in which
metal Ions are bound to proteins, nucleic acids and related ligands.
Here the metal ions are bound to huge polymeric ligands and give rise to
characteristic properties which are different from those of the corresponding low-
molecular weight analogues. a. Complex Formation of Metal Ions with Biopolymers
6-3-1 Metal complexes of Polypeptides
Metalloenzymes are generally formed between a polypeptide and metal ion. The
coordination structure of the complex, the conformation of the polypeptide which
is dependent on the sequence of the amino acids in the polypeptide, stiffness of the
backbone and the interaction between the pendent groups cause specificities in
metalloenzymes . The onset of coordination in polypeptides is generally by the
presence of sulphur, nltrogen and oxygen in various functional groups. The
coordination structures of the Cu(II) complexes of synthetic poly(amino acid)s are
generally dependent on the pH of the solution. Mainly these complexes are planar
or distorted planar. The coordination of poly(Lhistidine) with Cu(II) ions gave a
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 42
square-planar structure at pH 5. This square-planar complex is formed by the
coordination of three imidazolyl groups of histidine and one peptide nitrogen on the
main chain. At pH 14, a distorted square-planar structure is formed by
the coordination of four neighbouring peptide nitrogens with one imidazolyl group
coordinated at an apical position .
6-3-2 Metal Complexes of Nucleic Acids and Related Compounds
Due to the presence of negatively charged phosphate groups in RNA and DNA, their
structure can be stabilized only in the presence of positive charges like metal ions or
organic cations. The role of metal ions is to maintain higher structure or to participiate
in the replication, transcription or translation of DNA. Metal ions cause the
denaturation of DNA or RNA by binding to it.
6-4- Biomedical applications (Anti-bacterial activity and Anti-fungal activity)
These polymer metal complexes have been screened against several microorganisms
for their antimicrobial and antifungal activity; the results revealed that the polymer
metal complexes show superior anti-microbial activity than polymeric resin . It was
reported synthesis, characterization, and antimicrobial activities of phenylurea
formaldehyde resin (PUF) and its polymer metal complexes [PUF–M(II)]. The
antimicrobial activity of these resin were tested against six bacteria (Bacillus
subtelillis, Bacillus megaterium, Staphylococcu aureus, Escherichia coli,
Pseudomonas aeruginosa, Salmonella typhi) and six fungi (Candida albicans,
Tubercularia species, Aspergillus flavus, Aspergillus niger, Fusarium species, Mucer
species). Their findings was that the antimicrobial activity of the PUF–Cu(II) showed
the highest zone of inhibition because of its higher stability constant and may be used
in biomedical applications. (Ahamad & Alshehri. 2012)[40]
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 43
6-4-1Antimicrobial activity
Patel et al 2009 reported synthesize polymer-metal complexes of phenolic resin and
the its Antimicrobial activity of polymermetal complexes against Escherichia coli,
Bacillus subtilis, Staphylococcus aureus (bacteria) and Saccharomyces cerevisiae
(yeast) were measured. It is observed that polymer-metal complexes are efficient and
effective catalysts and antimicrobial agents.[41]
6-5- Polymeric Ligands in Metal Ion Separations
An important application of polymer supported ligands is in the selective separation
of metal ions and efforts in the recovery of metal ions from aqueous solutions using
polymeric chelating agents are steadily increasing. lo2-lo6. separation of metal ions is
realised only by using polymeric ligands and by making use of the dependencies of
the stability of the metal complex upon the structure of the ligands and the kind of
metal ions. Although it is possible to separate some definite metal ion from a mixture
of metal ions, it has not yet been possible to adsorb or complex any desired
metal ion selectively from a mixture of metal ions.
Removal, separation, and enrichment of hazardous metal ions in aqueous solutions
play an important role for environmental remediation of municipal and industrial
wastewater. Heterogeneous methods have been used for the separation of inorganic
ions contained in natural waters, industrial fluids, or dissolved solid materials.
The efficient and selective separation of inorganic ions can be achieved by using
water-soluble, polymeric reagents in combination with membrane filtration [42]. This
technique, developed in our laboratory, termed liquid-phase polymer-based retention
(LPR), is based on the separation of ions bound to water-soluble polymers with
chelating groups (polychelatogens) from noncomplexed ions [43,44,45]. It has found
application in the recovery of metals from diluted solutions both on an analytical and
technical scale.
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 44
6-6-Solar Energy
Dye-sensitized solar cells (DSSCs) have been proven to be a promising
alternative to conventional solar cells because of the low cost, abundant material
source, easy fabrication, and low energy consumption in the production processes
Jin et al 2013 reported that , It was successfully synthesized four D-π-A type main
chain polymericmetal complexes and used them as dye sensitizers in DSSCs. The
results show that the introduction of a strong electron donor thiophene and
phenanthroline derivative metal complexes to the molecular skeleton, which is
conducive to broaden the spectral absorption range of polymeric metal complexes.
In addition ,the study results show the four polymers exhibit good thermally stable
and the solar cells based on them have good device performance, and the
maximumpower conversion efficiency is up to 0.735% for the solar cells based on
P3with a short-circuit current (Jsc) of 1.68 mA/cm2 and an open-circuit voltage (Voc)
of 0.62V.[46]
6-7 Semi conductivity
The semiconducting properties of polymer metal complexes such as phthalocyanine,
polyferrocene. polyacetic acid metal complex, polyamino quinone
metal complex etc. have been well known and well studied.These are widely
employed in the research of semiconductors. ( Chacko - 2010 )[20]
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 45
Acknowledgements:
First of all I would like to thank Allah for his blessing and guidance without which I
could not finish this work. I would like also to thank the University of King Saud ,
School of Chemistry for Academic resources and facilities.
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 46
References:
[1]Lázaro, N., Sevilla, A.L., Morales, S. & Marqués, A.M. 2003, "Heavy metal
biosorption by gellan gum gel beads", Water research, vol. 37, no. 9, pp. 2118-2126. [2] Rhazi, M., Desbrières, J., Tolaimate, A., Rinaudo, M., Vottero, P. & Alagui, A.
2002, "Contribution to the study of the complexation of copper by chitosan and oligomers", Polymer, vol. 43, no. 4, pp. 1267-1276.
[3] I.U. Castro, F. Stuber, A. Fabregat, J. Font, A. Fortuny, C. Bengoa, Supported
Cu(II) polymer catalysts for aqueous phenol oxidation, J. Hazardous Materials 163 (2009) 809–815.
[4] S. Turmanova, K. Vassilev, S. Boneva, Preparation, structure and properties of metal–copolymer complexes of poly-4-vinylpyridine radiation-grafted onto polymer
films, Reactive & Functional Polymers 68 (2008) 759–767.
[5] J. Nagel, U. Oertel, Langmuir–Blodgett layers from polymer–metal complexes:behaviour of monolayers and preparation of multilayers, Polymer 36 (1995)381–386.
[6] T. Kaliyappan, C.S. Swaminathan, P. Kannan, Synthesis and characterization of a new metal chelating polymer and derived Ni(II) and Cu(II) polymer complexes, Polymer 37 (1996) 2865–2869.
[7] I.R. Kamrupi, S.K. Dolui, Synthesis of copper–polystyrene nanocomposite
particles using water in supercritical carbon dioxide medium and its antimicrobial activity, J. Applied Polymer Science 120 (2011) 1027–1033.
[8] I.R. Kamrupi, P. Phukon, B.K. Konwer, S.K. Dolui, Synthesis of silver–polystyrene nanocomposite particles using water in supercritical carbon dioxide
medium and its antimicrobial activity, J. Supercritical Fluids 55 (2011) 1089–1094. [9] Aleksandrova E. L., Goikhman M. Ya., Podeshvo I. V.," New light-sensitive
materials based on polymer-metal complexes " Kudryavtsev V. V.: J. Optical Technol. 2001, 68, 849
[10] Jeon C., Holl W.:application of surface complexation model to heavy metal sorption equilibria onto aminated chitosan. Hydrometallurgy 2004, 71, 421.
[11] Voges R .L . and Jones W .R . Macromolecules . 4, p .298(1971).
[12] Tomono T . Honda K. and Tsychid Yolym Sci ., Polym. Chem.Ed. 12, p.1243 (1974).
[13] Osada Y . MalaomaL Chem. 176, p .1983 (1975).
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 47
[14] Kurimara Y. Tsuchida L. and Kaneko MJ. JPolym.Sci. AL9, p .3511 (1971).
[15] Dingman J . Sigga S. and Barton C. And Chem. 44, p.1351, (1972).
[16] Thananjayan Kaliyappan and Palaninathan Kalman "Polymer-Metal Complexes . Synthesis and Characterization of Poly (2-Hydroxy-4-Acryloyloxy Acetophenone-
Formaldehyde)-Metal Complexes" Iranian J. of Polymer Science and Technology Vol 4 No 1 (1995)
[17] J. Jezierska, A.W. Trochimczuk, J. K˛edzierska, Coordinating properties of
polymers with N-substituted diamides of malonic acid towards Cu(II); EPR studies, Polymer 40 (1999) 3611–3616.
[18] K.H. Wu, Y.R. Wang, W.H. Hwu, FTIR and TGA studies of poly(4-vinylpyridine co-divinylbenzene)–Cu(II) complex, Polymer Degradation and Stability
79 (2003) 195–200.
[20 ] S Chacko - 2010 Polymer Supported Metal Complexes and Mixed Ligand Complexes: An Overview Chapter 2,
http://shodhganga.inflibnet.ac.in:8080/jspui/bitstream/10603/284/8/08_chapter2.pdf Some Examples of latest Polymer Metal Complexes Synthesis
[21] AHAMAD.T, ALSHEHRI .S.M 2013"Synthesis and Characterization of Polymer Metal Complexes and Their Catalytic Activity in Ethylene Oligomerization"
Advances in Polymer Technology, Vol. 32, No. 3, 2013, DOI 10.1002/adv.21350
[22]Cao, L., Ma, C., Wang, J. & Chen, P. 2013, "Synthesis of polymer–copper(II)
complexes in supercritical carbon dioxide", The Journal of Supercritical Fluids, vol. 75, no. 0, pp. 152-158.
[23] E. Tsuchida, H. Nishide, Polymer–metal complexes and their catalytic activity, Advances in Polymer Science 24 (1977) 1–87.
[24] I˙. Kaya, H.O¨ . Demir, A.R. Vilayetog˘lu, 2002 " Study on Synthesis,
Characterization, Thermal Stability and Conductivity Properties of a New Conjugated Oligoazomethine and some of its Metal Complexes" Synth. Met. 126 (2, 3) (2002)
183.
[25] Kaya.I, Baycan.F 2007 "Synthesis, characterization, conductivity, band gap and thermal analysis of poly-2-[(4-mercaptophenyl) imino methyl] phenol and some of its
polymer–metal complexes" Synthetic Metals 157 (2007) 659–669
[26]Jin, X., Deng, J., Wen, G., Yu, X. & Zhong, C. 2013, "Synthesis and photovoltaic properties of main chain polymeric metal complexes containing 1,10-phenanthroline
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 48
metal complexes conjugating alkyl fluorene or alkoxy benzene by C?C bridge for dye-sensitized solar cells", Polymers for Advanced Technologies, vol. 24, no. 2, pp.
266-269.
[27]M. V. Chirkova, P. V. Pivovarov , E. G. Litvinova, and V. S. Khotimskii2006 " Chemical Modification of Poly(vinyltrimethylsilane) and Poly(1-trimethylsilyl-1-propyne) Using Highly Reactive Metallating Systems. Polymer Science, Ser. A, 2006,
Vol. 48, No. 5, pp. 489–497.
[28]Jian-Cheng Zhang1, Jia-Dong Hua, Ke-Jian Zhang and Jin-Liang Zhu3 " Ion Beam Modification of the Complex of Polymer-Metal with Fullerene" 1995
,Australia
[29] B.C.E. Makhubela, A. Jardine, G.S. Smith, Rh(I) complexes supported on a biopolymer as recyclable and selective hydroformylation catalysts, Green Chemistry 14 (2012) 338–347.
[30] F.R. Diaz, J. Moreno, L.H. Tagle, G.A. East, D. Radic, " Synthesis,
characterization and electrical properties of polyimines derived from selenophene"Synth. Met. 100 (2) (1999) 187.
[31] K.I. Wagner, P.H. Aubert, L. Lutsen, D. Vanderzande, " Conjugated polymers based on new thienylene – PPV derivatives for solar cell applications"Electrochem.
Commun. 4 (2002) 912. [32] K. Colladet, M. Nicolas, L. Goris, L. Lutsen, D. Vanderzande, " Low-band gap
polymers for photovoltaic applications "Thin Solid Films 451–452 (2004) 7.
[33] Y. Li, Y. Cao, J. Gao, D. Wang, G. Yu, A.J. Heeger," Electrochemical properties of luminescent polymers and polymer light-emitting electrochemical cells" Synth. Met. 99 (1999) 243.
[34] X. Z. Li, W. J. Zeng, Y. Zhang, Q. Hou, W. Yang, Y. Cao, Eur. Polym. J. 2005, 41, 2923.
[35]Vogel, A. I. (1978). Textbook of quantitative inorganic analysis (4th ed.). London: Longman.
[36]West, T. S. (1969). Complexometry with EDTA and related reagents (3rd ed.). Pools, London: DBH Ltd.
[37] Mabbs, F. E., & Machin, D. T. (1973). Magnetism and transition metal
complexes. London: Chapman and Hall., pp. 5–6. [38] M. Cazacu, M. Marcu, A. Vlad, G.I. Rusu, M. Avadanei, J. Organometal. Chem.
689 (19) (2004) 3005.
Coordination Polymer &Polymer-Metal Complexes: Synthesis, Characterization, and Properties Page 49
[39] AHAMAD.T, ALSHEHRI .S.M 2013"Synthesis and Characterization of Polymer Metal Complexes and Their Catalytic Activity in Ethylene Oligomerization"
Advances in Polymer Technology, Vol. 32, No. 3, 2013, DOI 10.1002/adv.21350
[40]Ahamad, T. & Alshehri, S.M. 2012, "Synthesis, characterization and anti-microbial activity of phenylurea–formaldehyde resin (PUF) and its polymer metal complexes (PUF–Mn(II)", Spectrochimica Acta Part A: Molecular and Biomolecular
Spectroscopy, vol. 96, no. 0, pp. 179-187.
[41]Mihir Patel & Malav Kapadia & Jayantilal Joshi 2009 " Polymer-metal complexes of phenolic resin with Ln (III): thermal, catalytic and antimicrobial aspects " J Polym Res (2009) 16:755–765
[42] K. E. Geckeler, G. Lange, H. Eberhardt, E. Bayer. " Preparation and application
of water-soluble polymer-metal complexes "Pure Appl. Chem. 52, 1883 (1980).
[43] B. Ya. Spivakov, K. Geckeler, E. Bayer. Nature 315, 313 (1985).
44 323 . K. E. Geckeler, E. Bayer, B. Ya. Spivakov, V. M. Shkinev, G. A. Vorobeva. Anal. Chim.Acta 189, 285 (1986).
[45] K. E. Geckeler, V. M. Shkinev, B. Ya Spivakov. Sep. Purif. Methods 17, 105 (1988).
[46 ]Jin, X., Deng, J., Wen, G., Yu, X. & Zhong, C. 2013, "Synthesis and photovoltaic properties of main chain polymeric metal complexes containing 1,10-
phenanthroline metal complexes conjugating alkyl fluorene or alkoxy benzene by C?C bridge for dye-sensitized solar cells", Polymers for Advanced Technologies, vol.
24, no. 2, pp. 266-269.
[48 ] Raja Shunmugam, Gregory N. Tew* "Polymers that Contain Ligated Metals in
their Side Chain: Building a Foundation for Functional Materials in Opto-Electronic
Applications with an Emphasis on Lanthanide Ions " Macromol. Rapid Commun. 2008, 29, 1355–1362
[49]Priyadarshini, U and S.G. Tandon. 1967. Preparation and properties of some N-aryl hydroxyamic acids. Journal of Chemical Engineering Data. 12(1), pp.143-144
[50]Ukey, V.V., H.D. Juneja, S.D Borkar and S. Naz. 2006. Preparation, characterization, magnetic and thermal studies of some chelate polymers of first series transition metal ions. Materials Science and Engineering: B. 132(1-2) pp.34-38
[51]Craig, T.C., D.M. Ciurtin, M.D. Smith and H.Z. Loye. 2002. A new mixed-metal
Mn–Rh coordination polymer assembled from Mn-containing molecular building blocks and Rh2(OAc)4 dimers. Journal of Solid State Sciences. 4(9), pp. 1187–1191.