Synthesis and properties of iridium polymer complexes based on novel bipyridyl ligands

Article abstract of DOI:10.1007/s11172-012-0139-x

A novel monomer, viz., bipyridyl-containing dicarboxylic acid, was synthesized from 6-pyridyl-3,4-pyridine dicarboxylic acid anhydride and 5-aminoisophthalic acid. Novel polymer macroligands, viz., copolyamides containing 5, 15, 30, and 45% of the bipyrid

Full text of DOI:10.1007/s11172-012-0139-x

Russian Chemical Bulletin, International Edition, Vol. 61, No. 5, pp. 966—972, May, 2012
966
Synthesis and properties of iridium polymer complexes
based on novel bipyridyl ligands
M. Ya. Goikhman,a I. V. Podeshvo,a N. L. Loretsyan,a I. V. Gofman,a R. Yu. Smyslov,a T. N. Nekrasova,a
V. E. Smirnova,a A. A. Polevoi,b and A. V. Yakimanskiia
aInstitute of Macromolecular Compounds, Russian Academy of Sciences,
31 Bolshoi prosp., 199004 Saint Petersburg, Russian Federation.
Fax: +7 (812) 328 6869. Еꢀmаil: goikhman@hq.macro.ru
bDepartment of Chemistry, Saint Petersburg State University,
26 Universitetsky prosp., Petrodvorets, 198504 Saint Petersburg, Russian Federation.
Еꢀmail: alex.polevoy@mail.ru
A novel monomer, viz., bipyridylꢀcontaining dicarboxylic acid, was synthesized from
6ꢀpyridylꢀ3,4ꢀpyridine dicarboxylic acid anhydride and 5ꢀaminoisophthalic acid. Novel polymer
macroligands, viz., copolyamides containing 5, 15, 30, and 45% of the bipyridyl side groups,
were obtained based on this monomer by lowꢀtemperature polycondensation. Metal polymer
complexes (MPC) with different Ir(ppy)2 content were synthesized by the reaction of the
polymer ligand with the binuclear complex [Ir(ppy)2Cl]2 (ppy is 2ꢀphenylpyridine) and their
properties were studied.
Key words: 2ꢀpyridylquinoline, oxidation, decarboxylation, bipyridylꢀcontaining monoꢀ
mers, copolyamides, iridium, metal polymer complexes, luminescence.
The capability of nitrogenꢀcontaining heterocycles,
side bipyridyl groups and iridium polymer complexes based
on them, and to study their properties.
such as 1,10ꢀphenanthroline, 2,2´ꢀbiquinoline, and 2,2´ꢀbiꢀ
pyridyl, to form complex compounds with metal ions is
widely used in many fields of chemistry and technology.1—3
The complexes containing the aboveꢀmentioned ligands
find application in analytical chemistry and catalyst sysꢀ
tems, as well as working laser materials. In recent years,
a novel investigation step of transition metal complexes with
nitrogenꢀcontaining ligands came on, which is a step of
extensive investigation of their photophysical, spectralꢀ
luminescent, and electrochemical properties.4—7 Of speꢀ
cial interest are macromolecular ligands witn nitrogenꢀ
containing heterocyclic moieties in the polymer backbone
or side groups, which combine interesting physical propꢀ
erties with processibility and high performance. Among
a number of transition metal polymer complexes, the metal
polymer complexes (MPC) based on iridium provoke inꢀ
tense interest of investigators.8 At the same time, the artiꢀ
cles dedicated to the synthesis of polymers with ligand
groups, in particular, bipyridyl groups, are few.9 This is
obviously due to the difficulties occuring during the synꢀ
thesis of reactive bipyridyl derivatives, which can act as
monomers upon polymerization or polycondensation or
can be used for chemical modification of macromolecular
compounds. The aim of the present work is to develop the
synthetic procedure for a novel available bifunctional biꢀ
pyridylꢀcontaining monomers, to prepare polymers with
Results and Discussion
To prepare macromolecular ligands with side bipyridyl
groups, lowꢀtemperature polycondensation was used,
which allows preparation of highꢀmolecularꢀweight polyꢀ
mers having good stressꢀstrain properties and high therꢀ
mal stability. At the first step, it was necessary to obtain
the reactive bifuncitonal monomer for polycondensation
that contains the bipyridyl group. This problem was solved
by oxidation of 2ꢀ(2ꢀpyridyl)cinchonic acid. The general
synthetic scheme is given below.
According to Scheme 1, 2ꢀ(2ꢀpyridyl)quinolineꢀ4ꢀ
carboxylic acid (1) synthesized from isatin and 2ꢀacetylpyrꢀ
idine by the Pfitzinger reaction6 was oxidized with potasꢀ
sium permanganate in the alkaline medium. Under these
conditions, the benzene ring of quinoline fragment10 unꢀ
dergoes oxidation to form 6ꢀ(2ꢀpyridyl)pyridineꢀ2,3,4ꢀtriꢀ
carboxylic acid (2). The carboxyl group in the 2 position is
readly removed upon decarboxylation11 in a AcOH—Ac2O
mixture, cyclization involving the carboxyl groups in the 3
and 4 positions occuring simultaneously with decarboxylꢀ
ation to form 6ꢀ(2ꢀpyridyl)pyridineꢀ3,4ꢀdicarboxylic acid
anhydride (3). The bifunctional monomer for polymerizaꢀ
tion was synthesized by the reaction of compound 3 with
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 0961—0967, May, 2012.
1066ꢀ5285/12/6105ꢀ0966 © 2012 Springer Science+Business Media, Inc.

Copolymers with side bipyridyl groups
Russ.Chem.Bull., Int.Ed., Vol. 61, No. 5, May, 2012
967
Scheme 1
5ꢀaminoisophthalic acid. This reaction proceeds in two
steps: at the first step, the amido acid forms, which is
transformed without isolation to the imide by heating in
a Ac2O—Py mixture to yield 5ꢀ[6ꢀ(2ꢀpyridyl)ꢀ5ꢀazaꢀ
phthalimido]isophthalic acid (4). At the second step, the
reaction of 4 with thionyl chloride affords 5ꢀ[6ꢀ(2ꢀpyridꢀ
yl)ꢀ5ꢀazaphthalimido]isophthalic acid dichloride (5).
Based on dichloride 5 and 4,4´ꢀdiaminodiphenyl ether
(6), copolyamides 8a—d containing 5, 15, 30, and
45 mol.% of the units with side bipyridyl groups were synꢀ
thesized by lowꢀtemperature polycondensation (Scheme 2).
As a comonomer, terephthaloylꢀ[bis(3ꢀmethoxyꢀ4ꢀoxyꢀ
benzoic)] acid dichloride (7) was chosen, since, on its
basis, polyamides with a high inherent viscosity can be
obtained,12 whose films possess good thermal stability and
required mechanical characteristics.
The metal polymer complexes of iridium can be obꢀ
tained conveniently by the reaction of macromolecular
ligands with the binuclear bridged complex 9 (see Ref. 5).
By the reaction in the chain of copolyamides 8a—d
with complex 9, the metal polymer complexes 10a—d were
obtained (Scheme 3).
Table 1. Composition, inherent viscosity (), and mechanical and thermal characteristics of the films of coꢀPAs with different
concentrations of the units with side bipyridyl groups and MPCs based thereon
Copolymer
Copolymer composition (%)
Properties of films
n
p
q
[]/dL g–1
Е/GPa
 /MPa
 /MPa
 (%)
Tg/C
y
b
b
8a
10a
8b
10b
8c
10c
8d
5
2.8
3.0
2.2
2.4
1.8
2.0
1.4
1.7
4.18
4.22
4.12
4.04
3.94
3.95
3.88
3.82
140
**
136
135
140
**
205
139
174
180
165
124
157
112
35
4.8
29
31
21
8.3
19
5.0
221
221
224
238
230
264
237
316
1.25
5.55
11.4
14.4
3.75
9.45
18.6
30.6
15
30
45
138
**
10d
* E is Young´s modulus, y is a yield point, b is the ultimate deformation of a film, b is the ultimate strength of
a film before destruction, Tg is a glass transition point. ** The y values cannot be determined due to low strainꢀtoꢀ
destruction values of the material.

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Goikhman et al.
Scheme 2
8: n = 5 (a), 15 (b), 30 (c), 45 mol.% (d)
Scheme 3
The compositions of the metal polymer complexes
synthesized were established by elemental analysis and
1H NMR spectroscopy. The studies performed allowed us to
determine the portion of units containing the complex fragꢀ
ments. As for the most of macromolecular reactions, the
complex formation does not result in the complete converꢀ
sion of any of the polymer ligands synthesized. The degree
of modification is about 60—75% depending on the content
of side bipyridyl units (Table 1). Thus, the metal polymer
complexes 10a—d are tercopolymers where, along with the
units containing the complex fragments, there are units with
side bipyridyl groups underwent no complex formation.
All synthesized polymers 8a—d and the iridium polyꢀ
mer complexes 10a—d based on them possess high intrinꢀ
sic viscousity (see Table 1) and we succeeded in the prepaꢀ
ration of stable transparent films from solutions of these
polymers in Nꢀmethylꢀ2ꢀpyrrolidone.
10: p+q = 5 (a), 15 (b), 30 (c), 45 mol.% (d)
a noticeable effect on the properties of the copolyamide
(coꢀPA) films (see Scheme 2). As the content of units with
side bipyridyl groups in the macrochains grows, the
Young´s modulus values of films decrease steadily. Upon
The mechanical test results (see Table 1) evidence that
the concentration ratio of the m and n type units have

Copolymers with side bipyridyl groups
Russ.Chem.Bull., Int.Ed., Vol. 61, No. 5, May, 2012
969
/MPa
the increase in the concentration of these units from 5 to
45%, the Е value decreases from 4.18 to 3.82 GPa.
The observed decrease in the film rigidity reflects
changes in the characteristics of intermolecular bonding
system in the copolymer as the concentration of side groups
in the macrochains grows. It is known13 that the strucꢀ
tures of the polyamide films are characterized by the presꢀ
ence of the extensive system of intermolecular hydrogen
bonding, which results in high Young´s moduli of such
materials. The introduction of bulky side bipyridyl groups
to the chain decreases the concentration of these bonds.
When analyzing the intermolecular interactions in the
coꢀPAs under study, one should keep in mind a possible
formation of additional hydrogen bonds involving the niꢀ
trogen atoms of the bipyridyl groups in the systems with
such side fragments. However, when estimating the role of
these groups in the hydrogen bond formation, one should
take into account the fact that the nitrogen atom of the
side chain can interact with both adjacent macrochains
and the same main chain. Since upon introduction of the
bipyridyl groups to the macrochain, the Young´s moduli
of films decrease, one can assume that in the coꢀPAs unꢀ
der consideration, there occur interactions of the second
type, which result in a successive decrease in the concenꢀ
tration of intermolecular bonds in the polymer.
The same trend of the successive decrease in the coꢀPA
film rigidity with introducing the side groups to the
material is observed also when analyzing the change in
the yield stress of the material: y drops successively (see
Table 1).
Finally, the growth in the concentration of the units
containing bipyridyl groups leads to a gradual decrease in
the ultimate strain of the film (b) and, consequently, in the
strength (b). For example, upon the increase in the conꢀ
centration of these units from 5 to 45%, the deformability
drops almost twoꢀfold. However, strong (b > 100 MPa)
and sufficiently elastic films (b  19%) were obtained for
all coꢀPAs synthesized in the present work.
The MPC formation does not result in a noticeable
change in the modulus values of the films compared to the
starting coꢀPAs (see Table 1). At the same time, for the
most of the compositions under study, the complex forꢀ
mation leads to a considerable decrease in the ultimate
deformations of the films (to 5—8%). An exception to this
case is the composition containing 15% of the units with
side bipyridyl groups. For the films of such composition,
the complex formation proceeds virtually without decrease
in the elasticity (see Table 1). This makes it possible to
compare the stressꢀstrain curve shape of the films of coꢀPA
and the complex based on it (Fig. 1). The complex formaꢀ
tion results in no change in the character of the deformaꢀ
tion processes in the material. As judged by the stressꢀ
strain curve shapes and the results of visual observations of
the behaviour of the samples during the test, the strain
process in both materials occurs according to the mechaꢀ
160
2
1
120
80
40
5
10
15
20
25
30
 (%)
Fig. 1. Strain curves of the films of coꢀPA 8b (1) and MPC 10b (2).
nism of stressꢀinduced elastic deformation without neckꢀ
ing and any other manifestations of local strain.
As noted above, the experimental results suggest that
the introduction of bulky Ir(ppy)2 groups to the polymer
chains does not provoke in a noticeable change in the
modulus values of the films. This fact seems to be rather
unexpected. Indeed, these groups, especially if their conꢀ
centration is high (30—45%), must impede the formation
of a regular system of intermolecular interactions in the
material, which, in turn, must provoke the decrease in the
E values of the complex films compared to those for the
corresponding coꢀPAs. The absence of such effect in the
experiments performed suggests that, as a result of the
complex formation in the films, the formation of new inꢀ
termolecular bonds takes place, which compensates the
effect of "loosening" of the material structure due to the
presence of the bulky Ir(ppy)2 groups. As such alternative
type of intermolecular interactions, one can propose the
known interaction mechanism of the aromatic fragments
of these groups with different aromatic groups of adjacent
chains.14
As the studies on the relaxation transitions in the coꢀPA
and MPC films showed (see Table 1), the glass transition
points of coꢀPAs displace successively to the highꢀtemperꢀ
ature region with increasing the content of the units with
side bipyridyl groups in the polymer chains. The same
tendency is observed when analyzing the behavior of the
MPC films, a more intensive growth in Тg compared to
the films of the starting coꢀPAs being observed for these
films. With increasing the concentration of complexes,
the segmental mobility defrost, which is necessary for the
transformation of the sample from the glassy state to the
highꢀelasticity one, is made difficult. As a result, the glass
transition temperature increases, which was observed in
the studies performed.
The luminescence spectra of the metal polymer comꢀ
plexes in DMF are shown in Fig. 2. In a solution, a broad

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Russ.Chem.Bull., Int.Ed., Vol. 61, No. 5, May, 2012
Goikhman et al.
I (rel. units)
of the monomeric metalꢀbonding units, there occurs an
increase in the luminescence in a solution according to
the mass action law due to a more effective complex forꢀ
mation. With further increase in the local concentration
of the MPC with the IrI ion above 15 mol.% in a solution
of individual macromolecules, concentration quenching
of luminescence is beginning to manifest itself.16
For the copolymers with the optimum quantity of the
metalꢀbonding units, we varied the content of the IrI ions
(see Fig. 3). The analysis of the luminescence spectra
showed that a decrease in the [IrI] : [bipyridyl] ratio from
1 to 0.25 results in virtually the same decrease in the intenꢀ
sity of the luminescence band of the MPC, which conꢀ
firms the drawn conclusion on the absence of concentraꢀ
tion quenching for the chosen optimum ratio between the
ligand and unreactive monomer units.
75
50
25
2
4
1
3
500
600
700
800 /nm
Fig. 2. Dependence of the luminescence intensity (I) of soluꢀ
tions of MPCs in DMF on the composition of the copolymer:
10a (1), 10b (2), 10c (3), and 10d (4).
Experimental
luminescence band of the MPC with the IrI ions from 575
to 750 nm was observed in the red region of the visible
spectrum with the intensity maximum at 630 nm. On goꢀ
ing from solutions of the polymers under study to the selfꢀ
supporting films (Fig. 3), we observed a shift of the lumiꢀ
nescence spectral bands to the shortꢀwave region by
20—30 nm.
The results obtained agree well with the published
data15 for the solutions of lowꢀmolecularꢀweight iridium
complexes with the bipyridyl derivatives in MeCN, which
luminesce in the region of 620 nm.
The analysis of the spectra obtained (see Fig. 2) allows
one to conclude that the dependence of the luminescence
intensity of the MPC with the IrI ion on the copolymer
composition is of extreme nature with the intensity maxiꢀ
mum at 15 mol.% of the metalꢀbonding fragments. This
can be explained by the fact that, in the range to 15 mol.%
Purification of the starting compounds and solvents. 5ꢀAminoꢀ
isophthalic acid, isatin, 2ꢀacetylpyridine, potassium permangaꢀ
nate, Nꢀmethylꢀ2ꢀpyrrolidone, propylene oxide, Et2O, (Aldrich)
underwent no additional purification. Thionyl chloride, AcOH,
and Ac2O were purified by simple distillation with taking the
corresponding fraction: 75.5 C (thionyl chloride), 117—118 C
(AcOH), and 138—140 C (Ac2O). DMF was dried over calcium
hydride and distilled in vacuo (b.p. 76 C at 40 Torr), Py was
dried over potassium hydroxide and distilled (b.p. 114—115 С),
and 4,4´ꢀdiaminodiphenyl ether was purified by vacuum distillaꢀ
tion (m.p. 190—191 C).
Synthesis of the starting compounds and polymers. 2ꢀ(2ꢀPyrꢀ
idyl)quinolineꢀ4ꢀcarboxylic acid 1 was synthesized by the Pfitzꢀ
inger reaction from isatin and 2ꢀacetylpyridine according to the
previously described procedure.6
Terephthaloylꢀ[bis(3ꢀmethoxyꢀ4ꢀoxybenzoic)] acid dichlorꢀ
ide 6 was prepared according to the published procedure.12
The synthesis of tetrakis(2ꢀphenylpyridineꢀС2,N´)(ꢀdiꢀ
chloro)diiridium) (9) was performed according to a known proꢀ
cedure.5
I (rel. units)
Synthesis of 6ꢀ(2ꢀpyridyl)pyridineꢀ2,3,4ꢀtricarboxylic acid (2).
To a solution of compound 1 (10 g, 0.04 mol) in 15% aqueous
solution of KOH (20 mL), a solution of potassium permanganate
(39 g, 0.247 mol) in water (800 mL) was added with stirring. The
mixture was refluxed for 40 min, cooled to room temperature,
and manganese dioxide that formed was filtered off. Sulfuric
acid was added to the filtrate until a weakꢀacid reaction and the
solution was concentrated until potassium sulfate began to crysꢀ
tallize out, the K2SO4 precipitate was filtered off after cooling.
Sulfuric acid was added to the filtrate until a weakꢀacid reaction,
potassium 2ꢀpyridylꢀ4,5,6ꢀpyridine tricarboxylate being precipꢀ
itated. The precipitate was boiled in EtOH, filtered off, dried,
dissolved in water, and acidified with a solution of hydrochloric
acid to pH 3. The precipitate that formed was filtered off, washed
with a small amount of water, dried at 50 C in vacuo. The yield
was 7.5 g (71%), m.p. 250 С. 1H NMR (DMSOꢀd6), : 7.61 (dd,
1 H, H(4), J = 9.5 Hz, J = 2 Hz); 8.10 (t, 1 H, H(3), J = 9.5 Hz);
8.50 (d, 1 H, H(5), J = 9.5 Hz); 8.78 (d, 1 H, H(2), J = 8 Hz);
8.82 (s, 1 H, H(1)).
500
1
400
300
2
200
3
100
500
600
700
/nm
Fig. 3. The effect of the ligand : Ir(ppy)2 ratio (mol.%) in copolꢀ
ymer 10b on the luminescence intensity in the films: 1 : 1 (1),
1 : 0.5 (2), and 1 : 0.25 (3).

Copolymers with side bipyridyl groups
Russ.Chem.Bull., Int.Ed., Vol. 61, No. 5, May, 2012
971
Synthesis of 6ꢀ(2ꢀpyridyl)pyridineꢀ3,4ꢀdicarboxylic acid anꢀ
hydride (3). Acid 2 (4.5 g, 0.018 mol) was refluxed for 5 h in
a mixture of AcOH (180 mL) and Ac2O (18 mL), then 3/4 of the
solvent mixture was removed. The crystals that formed were
filtered off, washed with Et2O, and dried at 50 C in vacuo. The
yield was 2.9 g (73%), m.p. 190 C. 1H NMR (DMSOꢀd6), : 7.55
(dd, 1 H, Н(4), J = 9.5 Hz, J = 2 Hz); 8.02 (t, 1 H, H(3), J = 9.5 Hz);
8.45 (d, 1 H, H(5), J = 9.5 Hz); 8.55 (s, 1 H, H(6)); 8.76 (d, 1 H,
H(2), J = 8 Hz); 9.08 (s, 1 H, H(1)).
Synthesis of 5ꢀ[6ꢀ(2ꢀpyridyl)ꢀ5ꢀazaphthalimido]isophthalic
cid (4). To a solution of 5ꢀaminoisophthalic acid (1.6 g, 0.009 mol)
in DMF (35 mL) cooled to 0 C, compound 3 (2 g, 0.009 mol)
was added. The solution was stirred for 5 h at room temperature.
Ac2O (1.1 mL) and Py (0.27 mL) were added to the resulted
suspension. The mixture was refluxed for 5 h and, after cooling
to room temperature, poured to water. The resulted precipitate
was filtered off, washed with water, dried at 50 C in vacuo and
recrystallized from a DMF—water (1 : 1) mixture. The yield was
3 g (83%). 1H NMR (DMSOꢀd6), : 7.62 (dd, 1 H, H(4), J = 9.5 Hz,
J = 2 Hz); 8.08 (t, 1 H, H(3), J = 9.5 Hz); 8.33 (s, 2 H, H(7),
H(11)); 8.53 (d, 1 H, H(5), J = 9.5 Hz); 8.55 (t, 1 H, H(9),
J = 2 Hz); 8.79 (s, 1 H, H(6)); 8.83 (d, 1 H, H(2), J = 8 Hz); 9.36
(s, 1 H, H(1)), 13.57 (br.s, 2 H, H(8), H(10)).
From the resulted solutions of polymers, films were cast on
glass supports and dried at 200 С until a constant weight. The
film thickness was 6—25 m.
Synthesis of iridum polymer complexes. To a solution of comꢀ
pound 8b (0.0588 g, 9.5•10–5 mol) in Nꢀmethylꢀ2ꢀpyrrolidone
(2 mL), compound 9 (0.0063 g, 0.7•10–5 mol) was added. The
mixture was heated with stirring under argon for 10 h at 110 С
and, after cooling, poured to EtOH. The sedimented polymer
was purified by extraction in EtOH for 24 h, dried in vacuo, and
dissolved in Nꢀmethylꢀ2ꢀpyrrolidone. Films were cast on glass
supports, dried at 200 С until a constant weight. The film thickꢀ
ness is 6—25 m.
The procedure is given for MPC 10b containing 15% of the
bipyridyl units. Metal polymer complexes 10a, 10c, and 10d
containing 5, 30, and 45% of the bipyridyl units, respectively,
were synthesized according to the analogous procedure.
Complex 10a. Found (%): C, 68.61; H, 4.10; N, 4.86;
Cl, 0.07. C3690H2075N225O880Cl5Ir5. Calculated (%): C, 68.4;
H, 3.2; N, 4.9; O, 22.0; Cl, 0.27; Ir, 1.5. 1H NMR (DMSOꢀd6),
: 3.9 (s, 5.7 H, MeO); 7.05—8.4 (m, 19.5 H, Ar); 10.35 (s, 2 H, NH).
Complex 10b. Found (%): C, 67.2; H, 3.95; N, 5.52; Cl, 0.50.
C3870H2225N275O840Cl15Ir15. Calculated (%): C, 66.9; H, 3.2;
1
N, 5.5; O, 19.4; Cl, 0.8; Ir, 4.2. H NMR (DMSOꢀd6), : 3.9
Synthesis of 5ꢀ[6ꢀ(2ꢀpyridyl)ꢀ5ꢀazaphthalimido]isophthaloyl
dichloride (5). A solution of compound 4 (1 g, 0.003 mol) in
thionyl chloride (50 mL) was refluxed for 5 h. After termination
of heating, thionyl chloride (40 mL) was removed. The precipiꢀ
tate that formed was filtered off and dried at room temperature.
The yield was 1 g (91%). Found (%): C, 56.32; H, 2.19; Cl, 16.59;
N, 9.80. C20H19Cl2N3O4. Calculated (%): C, 56.36; Н, 2.13;
Cl, 16.64; N, 9.86; O, 15.02.
(s, 5.1 H, MeO); 7.05—8.4 (m, 22.8 H, Ar); 10.35 (s, 2 H, NH).
Complex 10c. Found (%): C, 65.05; H, 3.91; N, 6.67; Cl, 0.96.
C4140H2450N350O780Cl30Ir30. Calculated (%): C, 65.1; H, 3,2;
1
N, 6.4; O, 16.3; Cl, 1.4; Ir, 7.6. H NMR (DMSOꢀd6), : 3.9
(s, 4.2 H, MeO); 7.05—8.4 (m, 29.4 H, Ar); 10.35 (s, 2 H, NH).
Complex 10d. Found (%): C, 64.8; H, 3.65; N, 7.3; Cl, 1.43.
C4410H2675N425O720Cl45Ir45. Calculated (%): C, 63.5; H, 3.2;
1
N, 7.1; O, 13.8; Cl, 1.9; Ir, 10.4. H NMR (DMSOꢀd6), : 3.9
Synthesis of copolymers. To a solution of 4,4´ꢀdiaminodiꢀ
phenyl ether (0.1 g, 5•10–4 mol) in Nꢀmethylꢀ2ꢀpyrrolidone (3 mL)
cooled to –15 C, compound 5 (0.0324 g, 8•10–5 mol) and
terephthaloylꢀ[bis(3ꢀmethoxyꢀ4ꢀoxybenzoic)] acid dichloride
(0.217 g, 4.3•10–4 mol) were added. The suspension was stirred
for 40 min at –15 C, the cooling bath was removed, and propylene
oxide (0.1 mL) was added. After complete dissolution of dichloꢀ
rides, the mixture was stirred for 4—5 h at room temperature.
The procedure is given for copolymer 8b containing 15% of
the bipyridyl units. Copolymers 8a, 8c, and 8d containing 5, 30,
and 45% of the bipyridyl units, respectively, were synthesized
according to the analogous procedure.
Copolymer 8а. Found (%): C, 70.55; H, 3.81; N, 4.55.
C3560H2565N215O880. Calculated (%): C, 70.61; H, 3.83; N, 4.51;
O, 21.05. 1H NMR (DMSOꢀd6), : 3.9 (s, 5.7 H, MeO); 7.0—8.4
(m, 17.9 H, Ar); 10.35 (s, 2 H, NH).
Copolymer 8b. Found (%): C, 68.49; H, 4.02; N, 5.68.
C3540H2495N245O840. Calculated (%): C, 68.69; H, 4.03; N, 5.54;
O, 21.74. 1H NMR (DMSOꢀd6), : 3.9 (s, 5.1 H, MeO); 7.0—8.4
(m, 21 H, Ar); 10.35 (s, 2 H, NH).
(s, 3.3 H, MeO); 7.05—8.4 (m, 40.7 H, Ar); 10.35 (s, 2 H, NH).
The calculations were performed for copolymers 10a—d with
(m+p+q) = 100 for the case when the complex formation proꢀ
ceeds by 100%.
1H NMR spectra for 1% solutions were recorded on a Вruker
Аvanceꢀ400 (400 MHz) spectrometer using Me4Si as the interꢀ
nal standard.
Luminescence spectra were recorded on a LSꢀ100 (PTI®)
spectrofluorometer. The slit width of excitation and recording
monochromators was 1 mm at the reciprocal linear dispersion of
4 nm mm–1. Photoluminescence was excited by the wavelength
of 370 nm based on the absorption band of the MPC formed with
the IrI ions.
The inherent viscosities [] of polymers were determined on
a Ubbelohde instrument (solutions in DMF) at 20 C.
The uniaxial tensile tests of the films were performed using
an UTS 10 (UTStestsysteme, Germany) universal mechanical
test device. During testing, the Young´s modulus E, the yield
point  (as the intersection point of the tangents to the initial
y
linear section of the stressꢀstrain curve and to the section
of development of stressꢀinduced elastic deformation), strength
 and ultimate deformation  . The aboveꢀmentioned characꢀ
Copolymer 8c. Found (%): C, 68.75; H, 3.92; N, 6.72.
C3480H2390N290O780. Calculated (%): C, 68.81; H, 3.94; N, 6.68;
O, 20.57. 1H NMR (DMSOꢀd6), : 3,9 (s, 4.2 H, MeO); 7.0—8.4
(m, 25.3 H, Ar); 10.35 (s, 2 H, NH).
b
b
teristics were obtained by averaging of the test results for seven
samples.
Copolymer 8d. Found (%): C, 68.89; H, 3.89; N, 7.85.
C3420H2285N469O720. Calculated (%): C, 68.93; H, 3.84; N, 7.88;
O, 19.35. 1H NMR (DMSOꢀd6), : 3.9 (s, 3.3 H, MeO); 7.0—8.4
(m, 31.9 H, Ar); 10.35 (s, 2 H, NH).
The calculations were performed for copolymers 8a—d with
(m+n) = 100.
The glass transition temperatures of the films under study
were determined by the dynamic mechanical analysis on a DMA
242 C (NETZSCH) device. The measurements were performed
on a frequency of 1 Hz at the strain amplitude of 10 m at the
heating rate of 10 deg min–1. The basic dimensions of the samꢀ
ples are 1.5×10 mm. The glass transition points Tg were deterꢀ

972
Russ.Chem.Bull., Int.Ed., Vol. 61, No. 5, May, 2012
Goikhman et al.
mined by the position of the maximum on the temperature deꢀ
pendences of the mechanical loss tangent.
9. C.ꢀT. Chen, T.ꢀS. Hsu, R. J. Jeng, J. Polym. Sci.: Part A:
Polym. Chem., 2000, 38, 498.
10. T. L. Gilchrist, Heterocyclic Chemistry, 2nd ed., University
of Liverpool, Longman Scientific & Technical, Copublished
in the United States with John Wiley & Sons, Inc., New
York, 1985.
This work was financially supported by the Russian
Foundation for Basic Research (Project Nos 09ꢀ03ꢀ00408ꢀ
а and 11ꢀ03ꢀ12044ꢀofiꢀmꢀ2011).
11. Y. Oka, K. Omura, Chem. Pharm. Bull., 1975, 23(10), 2239.
12. M. Ya. Goikhman, I. V. Podeshvo, G. M. Mikhailov, Yu. G.
Baklagina, V. V. Kudryavtsev, S. V. Lukasov, M. F. Lebedeꢀ
va, N. V. Bobrova, Yu. N. Sazanov, G. N. Fedorova, M. V.
Mikhailova, I. P. Deineko, Zh. Prikl. Khim., 1997, 70, 312
[Russ. J. Appl. Chem. (Engl. Transl.), 1997, 70].
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lov, A. V. Yakimanskii, V. V. Kudryavtsev, Vysokomol. Soeꢀ
din., Ser. A, 2010, 52, 408 [Polym. Sci., Ser. A (Engl. Transl.),
2010, 52].
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Received November 2, 2011;
in revised form February 17, 2012