Synthesis and optical properties of copolymers of 4-aminostyrene with the side styrylquinoline chromophore groups

Article abstract of DOI:10.1007/s11172-011-0048-4

Successive molecular assembling in polymer chains furnished a series of the comb-shaped copolymers of 4-aminostyrene containing side styrylquinoline chromophore groups. Thermal, thermomechanical, spectroscopic, and luminescent properties of the polymers a

Full text of DOI:10.1007/s11172-011-0048-4

Russian Chemical Bulletin, International Edition, Vol. 60, No. 2, pp. 295—303, February, 2011
295
Synthesis and optical properties of copolymers of 4ꢀaminostyrene
with the side styrylquinoline chromophore groups
M. Ya. Goikhman, L. I. Subbotina, A. A. Martynenkov, M. A. Smirnov,
R. Yu. Smyslov, E. N. Popova, and A. V. Yakimanskii
Institute of Macromolecular Compounds, Russian Academy of Sciences,
31 Bolshoi prosp., 199004 St.ꢀPetersburg, Russian Federation.
Fax: +7 (812) 328 6869. Еꢀmail: goikhman@hq.macro.ru
Successive molecular assembling in polymer chains furnished a series of the combꢀshaped
copolymers of 4ꢀaminostyrene containing side styrylquinoline chromophore groups. Thermal,
thermomechanical, spectroscopic, and luminescent properties of the polymers and lowꢀmoꢀ
lecularꢀweight model chromophores were studied.
Key words: copolymers, reactions in chains, side groups, chromophores, styrylquinoline,
luminescence.
Styrylquinoline dyes are of special interest among
a wide range of organic luminophores, which lately attract
attention of researches as a basis for the development of
electroluminescent devices.1—3 The structure of these comꢀ
pounds provides a possibility to widely vary optical charꢀ
acteristics by introduction of substituents in both the styrꢀ
yl fragment and benzene ring of the quinoline system.
Styrylquinoline dyes can be used for the preparation of the
highꢀstrength optically transparent coatings by vacuum
deposition method. Another, no less important method
for the preparation of coatings containing the indicated
luminophores is the use of polymeric supports with the
fragments of styrylquinoline dyes in the main chain or in
the side groups.4
is accompanied by difficulties, for example, by inhibition
of the chain growth process with the functional groups of
monomer in the case of radical polymerization or difficulꢀ
ties in purification of monomers in the case of polyconꢀ
densation. One of the most reasonable approaches to the
solution of this problem is a successive molecular assemꢀ
bling of chromophore groups using reactions in the polyꢀ
mer chains. We found it interesting to synthesize lowꢀ
molecularꢀweight chromophores of styrylquinoline series
and copolymers of styrene with 4ꢀaminostyrene containꢀ
ing side styrylquinoline groups of various structure and
study their thermal, spectroscopic, and photoluminescent
properties.
Results and Discussion
It should be noted that two types of chromophoreꢀ
containing polymeric systems can be distinguished by the
method of introduction of chromophores into a polymeric
matrix: the systems, in which the chromophore molecules
are dispersed in the polymeric matrix,5—7 and the systems
with the chromophore groups covalently incorporated into
the main8,9 or side10—12 chains of polymers. Polymeric
systems of the first type have a number of significant disꢀ
advantages, among which first of all are limited compatiꢀ
bility of chromophores with the polymeric matrix and, as
a consequence, uneven distribution of the chromophores
within the sample; low temperatureꢀtime stability of the
photophysical properties as a result of the chromophore
diffusions and formation of their microcrystals inside the
polymeric matrix, as well as low optical quality of the
samples and high level of optical losses because of light
dispersion on the structural heterogeneities. Polymers with
the covalently attached chromophore groups do not have
such disadvantages. Synthesis of such polymers, as a rule,
Due to the specificities of chemical reactions in polyꢀ
meric chains caused by high viscosity of solutions of polyꢀ
mers, as well as by conformational effects eventually leadꢀ
ing to a decrease in the number of functional groups parꢀ
ticipating in the reaction, it is very difficult to achieve high
yields of products in polymer analogous reactions. Howꢀ
ever, these difficulties can be overcome using catalysts and
functional groups with high reactivity. The method of moꢀ
lecular assembling of side chromophore groups in polyꢀ
mers suggested in the present work is based on the reacꢀ
tion between amine and anhydride groups leading to the
formation of imide rings with subsequent reaction of the
activated methyl group of the quinoline ring with the aldeꢀ
hyde group.
Our choice of chemical structure of polymer was govꢀ
erned by the following suggestions: the polymer should
possess linear structure, have active side groups with the
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 288—296, February, 2011.
1066ꢀ5285/11/6002ꢀ295 © 2011 Springer Science+Business Media, Inc.

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Goikhman et al.
Scheme 1
molecular weight of the polymer being high enough for
the preparation of a selfꢀsupporting film or quality coatꢀ
ing. Among widely used materials, functionalized polyꢀ
mers obtained, as a rule, based on traditional polymers,
for example, polyalkyl acrylates or polystyrene, with variꢀ
ous side functional groups (hydroxy, carboxy, amino
groups, etc.) are of particular interest. The presence of
reactive functional groups in the side chain opens wide
prospects for chemical modification of the polymers indiꢀ
cated and development qualitatively new materials on their
basis possessing a complex of valuable properties.
Scheme 2
The fact that copolymers of styrene are capable of formꢀ
ing thin transparent coatings,13,14 makes them promising
as optically active polymeric materials. Aminated polystyꢀ
rene is one of the representatives of this series of polymers,
the synthesis of which usually includes three steps: polyꢀ
merization of styrene, nitration of polystyrene obtained,
and subsequent reduction of the incorporated nitro groups
to amino groups. Another synthetic approach to the prepꢀ
aration of polystyrene containing amino groups attached
to the benzene rings consists in the direct use of the amiꢀ
noꢀcontaining monomer, i.e., 4ꢀaminostyrene, in the proꢀ
cess of polymerization. However, as it was noted in the
literature,15—18 polymerization of 4ꢀaminostyrene or its
copolymerization with styrene gives polymers of very low
molecular weight and in very low yield. This fact can be
explained by a partial transfer of electron density from the
amino group to the vinyl group conjugated with it, that
hinders the reaction of the latter with the free radical of
initiator or growing polymeric chain.16
3: n = m = 50%
In this connection, it was suggested to use 4ꢀaminostyꢀ
rene as a monomer for polymerization, whose amino group
is protected by the group readily removable after polymerꢀ
ization, for example, Nꢀtertꢀbutoxycarbonylꢀ4ꢀaminostyꢀ
rene (Bocꢀ4ꢀaminostyrene),16 that allowed one to obtain
polymers with acceptable characteristics.
Bocꢀ4ꢀaminostyrene 1 was obtained from 4ꢀaminostyꢀ
rene by the action of diꢀtertꢀbutyl dicarbonate (Boc2O) in
dioxane (Scheme 1).
the protons of the tertꢀbutyl group (δ 1.5) and the protons
of the phenyl ring (δ 6.2—7.2), the synthesized polyꢀ
[(styrene)ꢀcoꢀ(Nꢀtertꢀbutoxycarbonylꢀ4ꢀaminostyrene)]
(2) has proportion of the styrene and Bocꢀ4ꢀaminostyrene
units virtually unchanged as compared to the starting mixꢀ
ture and equal to 50—52 mol.% of Bocꢀ4ꢀaminostyrene
units. This indicates that the reactivity of comonomers is
close under conditions of copolymerization chosen. Earlier,
it has been shown16 that Bocꢀ4ꢀaminostyrene 1 possesses
a somewhat higher reactivity in copolymerization in toluꢀ
ene as compared to styrene, which results in the fact that
even if the content of comonomers in the starting mixture
is equimolar, the copolymer is somewhat enriched with
Bocꢀ4ꢀaminostyrene units (57 mol.%).
Bocꢀ4ꢀaminostyrene 1 obtained in such a way was used
for the synthesis of its copolymer with styrene. The copoꢀ
lymerization was carried out at 75 °C in N,Nꢀdimethylꢀ
acetamide (DMA) using 2,2´ꢀazobisisobutyronitrile (AIBN)
as an initiator (Scheme 2). The starting mixture of monoꢀ
mers consisted of Bocꢀ4ꢀaminostyrene and styrene taken
in equimolar amounts.
As it follows from the 1H NMR spectroscopic data, to
be exact, from the comparison of intensities of signals for
According to the GPC data, copolymer 2 is characterꢀ
ized by the following molecular masses: Mn = 33000,

Copolymers with styrylquinoline groups
Russ.Chem.Bull., Int.Ed., Vol. 60, No. 2, February, 2011
297
Mw = 71000. Provided that the average molecular weight
of the monomeric unit is 161.5, this corresponds to the
following degrees of polymerization (N): Nn = 204, Nw = 440.
The polydispersity index is ~2.15 that is characteristic of
polymers obtained by freeꢀradical polymerization.
Removal of the Boc protection was carried out with
the solution of trifluoroacetic acid (TFA) in dichloroꢀ
methane (see Scheme 2).
resulting in poly[(styrene)ꢀcoꢀ(4ꢀaminostyrene)ꢀcoꢀ(4ꢀ(4ꢀ
methylꢀ1,3ꢀdioxoꢀ1,3ꢀdihydropyrrolo[3,4ꢀc]quinolinꢀ2ꢀ
yl)styrene)] (6) (Scheme 4).
Scheme 4
2ꢀMethylꢀ3,4ꢀquinolinedicarboxylic acid anhydride
has been chosen as a basis for the side chromophore unit,
allowing one to obtain a polymer with the styrylquinoline
groups in the final step of the synthesis. The former was
successfully added to the polymeric chain by the formaꢀ
tion of imide rings at the amino groups of copolymer 3.
2ꢀMethylꢀ3,4ꢀquinolinedicarboxylic acid (4) was syntheꢀ
sized from isatin and ethyl acetoacetate by the Pfitzinger
reaction. The anhydride ring closure in the presence of
pyridine and acetic anhydride at 60 °C results in the forꢀ
mation of 2ꢀmethylꢀ3,4ꢀquinolinedicarboxylic acid anꢀ
hydride (5) (Scheme 3).
Scheme 3
6: n = 50%, k = 10%, m = 40%
1
The H NMR spectral data allowed one to calculate
the fraction of units containing 2ꢀmethylquinoline groups
in polymer 6. Copolymer 6 contains about 40 mol.% of
such units.
It is known that the methyl group at position 2 of the
quinoline ring possesses high reactivity and can be inꢀ
volved into different reactions, including reactions with
aromatic aldehydes, i.e., the Knoevenagel reaction19,20
(Scheme 5).
In the first step of molecular assembling of side chroꢀ
mophore groups, it was necessary to introduce 2ꢀmethꢀ
ylquinoline groups in polymer 3. To achieve this, anhyꢀ
dride 5 was added to the polymeric chain due to the forꢀ
mation of imide rings at the amino groups of copolymer 3.
In the first step, copolymer containing amic acid fragment
was obtained. In the second step, chemical imidizaꢀ
tion promoted by acetic anhydride and pyridine mixture
The very process, which is common in the preparation
of styrylquinoline chromophores,21 has been chosen for
the formation of side chromophore groups by polymer
analogous transformations.
Chemical reactions of aromatic aldehydes with copoꢀ
lymer 6 was carried out on reflux in oꢀdichlorobenzene
(oꢀDCB) using piperidine as a catalyst. The synthesized coꢀ
polymers 7a—d are well soluble in chloroform.

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Goikhman et al.
Scheme 5
n = 50%, k = 10%, m = 35—15%, s = 5—25%
Scheme 6
Copolymers 7a—d are compounds including units of
four different types: the fragments of styrene (n) and
4ꢀaminostyrene (k), units of 4ꢀ(4ꢀmethylꢀ1,3ꢀdioxoꢀ1,3ꢀ
dihydropyrrolo[3,4ꢀc]quinolinꢀ2ꢀyl)styrene (m), and chroꢀ
mophoreꢀcontaining units (s), viz., 2ꢀphenylꢀ4ꢀstyrylpyrꢀ
rolo[3,4ꢀc]quinolineꢀ1,3ꢀdione derivatives. The ratio of
units n : k : m : s in copolymers was determined using
1H NMR and UV spectroscopy.
Model compounds were synthesized to calculate the
molar content of chromophoreꢀcontaining units in the
copolymers. 4ꢀMethylꢀ2ꢀpꢀtolylpyrrolo[3,4ꢀc]quinolineꢀ
1,3ꢀdione (8) was obtained first, which was the basis for
the synthesis of model compounds 9a—d by the Knoeveꢀ
nagel reaction (Scheme 6).
The absorption maxima and extinction ratios of the
main model compound 8 and lowꢀmolecularꢀweight modꢀ
els of units with styrylquinoline chromophores 9a—d
synthesized on its basis, as well as copolymers 7a—d are
given in Tables 1 and 2, respectively. As it can be seen
from the data in Table 1, the longꢀwave absorption band
of compound 8 in the region 355 nm of the UV spectra
overlaps with absorption bands of all the models except
9a, which has λmax1 = 413 nm. Because of such an overꢀ
lap, it is impossible to determine the fraction of units with
styrylquinoline chromophore groups using only optical
density values at λmax. However, separation of extinction
ratios of quadruple copolymers at different wavelengths
(Fig. 1) to the analogous dependences for copolymer 6
and chromophores 9a—d using matrix method allowed us
to determine composition of copolymers 7a—d. Results of
spectrophotometric measurements allowed us to deterꢀ
mine extinction ratios of synthesized copolymers and model
chromophores within entire range of wavelengths studied.
Using spectra of model chromophores 9a—d and triple
copolymer 6 as a basis, we carried out computer separaꢀ
tion of the spectra of quadruple copolymers, solving the
redetermined system of equations of the form:
,
,

Copolymers with styrylquinoline groups
Russ.Chem.Bull., Int.Ed., Vol. 60, No. 2, February, 2011
299
Table 1. Absorption maxima and exctinction coefficients of
model compounds 8 and 9a—d
ε/L g–1 cm–1
40
Compound
λ
max/nm
ε/L mol–1 cm–1
8
260
324
355
32000 1000
03570 4000
04250 7000
39000 3000
17000 1000
32000 1500
37700 6000
04700 2000
23700 2000
30
9a
9b
405—413
277
3
4
20
10
2
356
333
405
325
9c
9d
1
300
350
400
450
λ/nm
where c1 and c2 are the unknown concentrations of the
quinolineꢀcontaining units and styrylquinoline units in
solutions of copolymers 7a—d characterizing its composiꢀ
tion; εi,1 and εi,2 are the extinction ratios of copolymer 6
and model chromophores at the wavelength λi; Di is the
optical density of solution of the quadruple copolymer at
the wavelength λi.
Fig. 1. Electronic absorption spectra of copolymer 6 (1), model
chromophore 9b (2), and copolymer 7b (3) in chloroform, and
theoretically calculated total spectrum of model 9b and coꢀ
polymer 6 (4).
agrees with the experimental spectrum of copolymer 7b
(curve 3). Analysis for all the synthesized polymers and
determination of their composition were carried out simiꢀ
larly: the results are given in Table 3. The maximum conꢀ
tent (28%) of chromophoreꢀcontaining units (s) was found
for copolymer 7a, copolymer 7b contains 22% of chromoꢀ
phore groups, copolymer 7d — about 21%. The least fracꢀ
tion of chromophoreꢀcontaining units (3%) was found in
copolymer 7c.
This system can be solved by the least squares methꢀ
od,22 whose matrix expression has the form
C = [(ETE)–1ET]D,
where C is the concentration vector {c1, c2}, E is the matꢀ
rix of extinction ratios of the models
The content of the covalently attached styrylquinoline
chromophores in the side chains of copolymers determined
using H NMR spectroscopy generally is in good agreeꢀ
,
1
D is the vector of optical densities of quadruple copolymer
{D1...Dn}.
ment with the results obtained from the UV spectra (see
Table. 3).
Figure 1 shows an example of expansion of the absorpꢀ
tion spectra for copolymer 7b and lowꢀmolecularꢀweight
model 9b corresponding to it. It is seen that the total
spectrum (curve 4) of the triple copolymer 6 and the model
obtained with the formula Di = c1εi,1 + c2εi,2 satisfactorily
Polymers meant for the use in optics are frequently
exposed to heat (for example, upon laser irradiation or
passing the electric current through), therefore, in order to
determine the temperature range of operation of new
chromophoreꢀcontaining polymers, it was necessary to
Table 2. Absorption maxima and exctinction coefficients
of copolymers 6 and 7a—d
Table 3. Composition of copolymers 6 and 7a—d acꢀ
cording to the 1H NMR and UV spectroscopic data
Compound
λ
max/nm
ε/L g–1 cm–1
64
8.5 0.3
8.4 0.2
45 3
44.3 0.5
31.4 0.3
Compound
Proportion of units (mol.%)
n : k : m : s
6
259
326
353
406
258
353
260
334
264
323
2
1H NMR
UV
6*
7a
7b
7c
7d
02 : 11 : 37
58 : 6 : 36
7a
7b
52 : 11 : 12 : 25
52 : 11 : 22 : 15
52 : 11 : 34 : 3
52 : 11 : 17 : 20
58 : 6 : 8 : 28
58 : 6 : 14 : 22
58 : 6 : 33 : 3
58 : 6 : 15 : 21
7c
7d
65
16
27
28
4
2
1
1
* For copolymer 6 the n : k : m proportion of units
is given.

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Goikhman et al.
I (rel. unit)
study their general thermal properties: indices of thermal
stability and temperature transitions. Method of DSC and
TGA were used to solve this problem (Table. 4).
a
It was shown that the temperature of 383 °C correꢀ
sponds to the index of thermal stability (τ5) of the starting
copolymer. Introduction of thermally stable imide heteroꢀ
cycles in the side groups does not lead to the increase in
thermal stability of copolymer 6 as compared to the startꢀ
ing copolymer 3, rather, it leads to its insignificant deꢀ
crease. This is due to the fact that thermal stability of
carbochain polymers is largely determined by the strucꢀ
ture of their main chain, which in the process of polymer
analogous transformations remains unchanged. At the
same time, general mobility of the system in the process of
chemical modification regularly increases because of deꢀ
crease in density of the hydrogen bonds net, presenting
due to the amino groups, and appearance of bulky side
substituents hindering intermolecular interactions, that
leads to the decrease in thermal stability of the polymer.
It should be noted that introduction of quinolineimide
groups in the side chains considerably increased the glass
transition temperature from 138.6 °C for the starting coꢀ
polymer 3 to 197.6 °C for copolymer 6. For copolymers
7a—d containing styrylquinoline units, the glass transiꢀ
tion temperature is within 190—230 °C.
200
100
300
I (rel. unit)
350
400
λ/nm
b
200
1
100
Study of luminescence of coatings prepared from soluꢀ
tions of copolymers synthesized, in particular, showed that
copolymer 3 exhibits luminescence in the UV region of
the spectrum (Fig. 2, a) with the intensity 250 arb. units at
2
λ
exc = 260 nm, whereas copolymers 7a—d actively absorb
500
600
λ/nm
in this region. At the same time, it was found that copoꢀ
lymers 7b,d possess noticeable luminescence in the orange
region of the spectrum. The maximum intensity of lumiꢀ
nescence in the region 590—600 nm is 105 arb. units at
Fig. 2. Luminescence spectra: copolymer 3 at λexc = 260 nm (a)
and copolymers 7b (1) and 7d (2) at λexc = 352 nm (b).
exc = 352 nm for copolymer 7b (Fig. 2, b). It is known23
transitions.23 Probability of such transitions is low, that is
indicated by low extinction ratios in longꢀwave region of
the spectrum (<2000 L mol–1 cm–1), as compared to the
π*—πꢀtransitions, for which εmax has an order of 104. This
explains comparably low intensities of luminescence of
copolymers 7b,d in the visible region.
In conclusion, copolymers of 4ꢀaminostyrene with the
side styrylquinoline chromophore groups were synthesized by
successive molecular assembling, their composition was
determined, and spectroscopic and thermal properties were
studied. It was shown that some of chromophoreꢀcontaiꢀ
ning copolymers studied possess good luminescent properties.
Based on polymers with styrylquinoline groups, it is
possible to obtain metalꢀpolymeric IrIII complexes, that
allows one to considerably increase their luminescent charꢀ
acteristics.24 In addition, styrylquinoline chromophores
possess high values of molecular quadruple polarizability,4
therefore, polarized films of such copolymers can demonꢀ
strate nonlinear optical properties of the second order.
Thus, the synthesized copolymers can be considered as
promising optically active materials.
λ
that for the intensity of luminescence to be high in the
visible region of the spectrum, the presence of π*—πꢀtranꢀ
sitions characterizing by high energies is required in the
system of conjugated bonds of chromophore groups. In
the case of copolymers 7b,d, there are π*—nꢀtransitions
due to the presence of the lone pair of electrons on the
nitrogen atom of the quinoline ring, rather than π*—πꢀ
Table 4. Thermal properties of chromophoreꢀcontaining
copolymers
Copolymer
TGA
DSC
Tg/°С
τ /°С
τ
10/°С
Coke (%)
5
3
6
7a
7b
7c
7d
383
373
395
350
345
355
393
390
406
380
379
390
3.0
37.2
36.0
18.0
23.5
34.6
138.6
197.6
223.0
204.3
196.4
207.5

Copolymers with styrylquinoline groups
Russ.Chem.Bull., Int.Ed., Vol. 60, No. 2, February, 2011
301
0.012 mol), and a solution of AlBN (0.039 g, 1 wt.%) in DMA
(5 mL) were placed into a 15ꢀmL tube. The tube was evacuated
at cooling with liquid nitrogen. The sealed tube was kept for 72 h
at 75 °C. The copolymer obtained was precipitated in methanol
(100 mL), filtered off, and dried for 24 h at 50 °C to obtain
Experimental
Solvents (DMF and DMA) were dried over calcium hydride
and distilled in vacuo. Styrene, oꢀDCB, anisaldehyde were puriꢀ
fied by vacuum distillation. Pyridine and 1,4ꢀdioxane were dried
over potassium hydroxide and purified by simple distillation.
Acetic anhydride and piperidine were purified by simple distillaꢀ
tion; AIBN was recrystallized from ethanol; isatin, ethyl acetoꢀ
acetate, Boc2O, 4ꢀbromobenzaldehyde, 4ꢀN,Nꢀdimethylaminoꢀ
benzaldehyde, benzaldehyde, light petroleum, chloroform,
dichloromethane, and TFA were used without additional purifiꢀ
cation.
1H NMR spectra of 1% solutions were recorded on an
Avanceꢀ400 spectrometer (Bruker, Germany) (400 MHz) using
Me4Si as an internal standard. Electronic spectra of solutions of
chromophore and copolymer models in chloroform were obꢀ
tained on a SFꢀ2000 spectrophotometer (OKB Spectrum) in the
region 250—500 nm with the 1ꢀnm step and range of concentraꢀ
tions 5•10–6—5•10–5 mol L–1. Luminescence spectra were reꢀ
corded on a LSꢀ100 spectrophotometer (PTI, Canada). The
width of inꢀ and outcoming slit was 4 nm. The wavelength of the
exciting light was varied from 380 to 230 nm.
1
copolymer 2 (3 g, 78%). H NMR (CDCl3), δ: 1.38 (br.s, 4 H,
H(1)); 1.54 (s, 9 H, But); 1.86 (br.s, 2 H, H(2)); 6.2—7.2 (br.m,
10 H, H(3)—H(7), NH).
Poly[(styrene)ꢀcoꢀ(4ꢀaminostyrene)] (3). A solution of coꢀ
polymer 2 (3 g in a mixture of TFA and dichloromethane (15 mL)
was stirred with magnetic stirrer for 3 h at room temperature.
The solvent and excess of TFA were evaporated on a rotary
evaporator, the residue obtained was dissolved in DMF and preꢀ
cipitated into ethanolic NaOH. A white precipitate that formed
was filtered off and dried for 24 h at 40—50 °C to obtain copolyꢀ
mer 3 (1.9 g, 92%). 1H NMR (CDCl3), δ: 1.43 (br.s, 4 H, CH2);
1.89 (br.s, 2 H, CH); 3.36 (br.s, 2 H, NH2); 6.2—7.2 (br.m, 9 H,
H(3)—H(7)).
2ꢀMethylquinolineꢀ3,4ꢀdicarboxylic acid (4) was obtained acꢀ
cording to the known procedure.25 1H NMR (CDCl3), δ: 2.9
(s, 3 H, Me); 7.76 (t, 1 H, H(2), J = 7.6 Hz); 7.93 (t, 1 H, H(3),
J = 7.6 Hz); 8.19 (d, 1 H, H(4), J = 8.8 Hz); 8.89 (d, 1 H, H(1),
J = 9.0 Hz).
2ꢀMethylquinolineꢀ3,4ꢀdicarboxylic anhydride (5). Acetic
anhydride (16 mL, 0.17 mol)) was added to a mixture of
2ꢀmethylquinolineꢀ3,4ꢀdicarboxylic acid (4 g, 17.3 mmol) and
anhydrous pyridine (12 mL) at 60—70 °C with continuous stirꢀ
ring. The reaction mixture was heated for 6 h at 60—70 °C,
cooled to 8 °C, and kept for 24 h. A precipitate that formed was
filtered off, washed with diethyl ether, and dried in vacuo at
60 °C to obtain anhydride 5 (2.98 g, 81%) as yellow crystals, m.p.
225—226 °C. Found (%): C, 67.81; H, 3.43; N, 6.35; O, 22.41.
C12H7NO3. Calculated (%): C, 67.61; H, 3.31; N, 6.57; O, 22.51.
Poly[(styrene)ꢀcoꢀ(4ꢀaminostyrene)ꢀcoꢀ(4ꢀ(4ꢀmethylꢀ1,3ꢀdiꢀ
oxoꢀ1,3ꢀdihydropyrrolo[3,4ꢀc]quinolinꢀ2ꢀyl)styrene)] (6). Anhyꢀ
dride 5 (1.1 g, 5.16 mmol (3% excess)) was added in one portion
to a solution of copolymer 3 (1.2 g) in DMF (22.8 mL), cooled to
–10 °C in the flow of argon with stirring. The reaction mixture
was stirred for 1 h at –10 °C, then for 6 h at room temperature,
and kept for 10 h. Pyridine (0.3 mL) and acetic anhydride
(0.6 mL) were added into the reaction mixture, which was stirred
for 6 h at room temperature. Then, the reaction mixture was
heated to 60 °C and stirred for 1 h. A solution of copolymer was
precipitated into 2% aq. Na2CO3 (100 mL). A precipitate that
formed was filtered off, washed with water, EtOH, and dried.
Copolymer 6 was purified by reprecipitation from the solution in
chloroform with light petroleum. The yield was 1.5 g (74%).
1H NMR (CDCl3), δ: 1.53 (br.s 20 H, H(1)); 1.92 (br.s 10 H,
H(2)); 2.55—3.15 (br.m, 12 H, Me), 6.25—7.25 (br.m, 47 H,
H(3)—H(8)); 7.35—8.89 (br.m, 16 H, H(9)—H(12)). Intensities
of signals were calculated taken n + k + m = 10.
Study of copolymers by GPC was carried out on an Agilent
1200 instrument (using DMA—0.05 M LiBr as an eluent, with
the rate of elution being 0.7 mL min–1, pressure was 67—70 Bar,
and temperature was 60 °C) with the UV detection on the waveꢀ
length 260 nm and calibration on polystyrene standards in DMA.
Elemental analysis was performed on a Vario EL analyzer (Eleꢀ
mental, Germany).
Thermal testing of samples was carried out on the following
instruments from Netzsch:
1) a TG 209 F1 thermomicrobalance, measurements were
carried out in the range of temperatures from 30 to 500 °C at the
rate of heating 10 °C min–1 under argon atmosphere, argon was
passed through the thermomicrobalance at 10 mL min–1, the
weight of samples was 1—2 mg;
2) a DSC 204 F1 differential scanning calorimeter of therꢀ
mal flow, tests were carried out in the range of temperatures
from 30 to 270 °C at the rate of heating 10 °C min–1 under argon
atmosphere, argon was passed through the sample at 25 mL min–1
the measurement cell was purged with argon at 70 mL min–1
the weight of samples was 2—3 mg.
,
,
Bocꢀ4ꢀaminostyrene (1). A solution of Boc2O (2.75 g,
12.6 mmol) in 1,4ꢀdioxane (10 mL) was added dropwise to
a solution of 4ꢀaminostyrene (1 g, 8.4 mmol) in 1,4ꢀdioxane
(20 mL) at 0 °C with continuous stirring in the flow of argon over
30 min. Then, the cooling was removed and the stirring was
continued for 3 h at room temperature. The solvent was evapoꢀ
rated on a rotary evaporator, an oily residue was mixed with
ethyl acetate, 10% aqueous KHSO4 was added to рH 4.5, the
mixture obtained was washed with water (3×100 mL), dried with
MgSO4, and the solvent was evaporated. A precipitate that formed
was filtered off, dried, recrystallized from nꢀhexane to obtain
compound 1 (1.35 g, 73%) as white crystals, m.p. 86—87 °C.
1H NMR (CDCl3), δ: 1.51 (s, 9 H, But); 5.15 (d, 1 H, =CH2,
J = 22.0 Hz); 5.64 (d, 1 H, =CH2, J = 35.4 Hz); 6.58—6.71
(m, 2 H, CH=, NH); 7.33 (s, 4 H, Ar). Physicochemical and
spectroscopic characteristics of Bocꢀ4ꢀaminostyrene 1 agree with
those given in the literature.16
Preparation of modified polymers 7a—d (general procedure).
A mixture of copolymer 6 (0.35 g, 0.7 mmol on the Me groups of
the quinoline ring), oꢀDCB (9.5 mL) and the corresponding
aldehyde (1.05 mmol) was heated to boiling, piperidine (1 drop)
was added, and the mixture was refluxed for 4 h. The solution
was cooled and poured into EtOH (100 mL), a precipitate that
formed was filtered off, washed with EtOH, and dried. Copolyꢀ
mers 7a—d obtained were repricipitated from solutions in chloroꢀ
form into light petroleum. In the 1H NMR spectra of copolyꢀ
mers 7a—d, signals related to the units n, k, and m are identical
Poly[(styrene)ꢀcoꢀ(Nꢀtertꢀbutoxycarbonylꢀ4ꢀaminostyrene)]
(2). Styrene (1.248 g, 0.012 mol), Bocꢀ4ꢀaminostyrene 1 (2.628 g,

302
Russ.Chem.Bull., Int.Ed., Vol. 60, No. 2, February, 2011
Goikhman et al.
to the corresponding signals of copolymer 6. Signals for the proꢀ
tons of units s are given below.
4ꢀ(4ꢀMethoxystyryl)ꢀ2ꢀ(pꢀtolyl)pyrrolo[3,4ꢀc]quinolineꢀ1,3ꢀ
dione (9b). Yellow crystals. The yield was 69%, m.p. 247—249 °C.
1H NMR (CDCl3), δ: 2.45 (s, 3 H, H(1)); 3.78 (s, 3 H, OMe);
7.06 (d, 2 H, H(12), H(13), J = 8.7 Hz); 7.35 (s, 4 H,
H(2)—H(5)); 7.72 (d, 2 H, H(14), H(15), J = 8.6 Hz); 7.83
(t, 1 H, H(7), J = 8.0 Hz); 8.01 (t, 1 H, H(8), J = 8.0 Hz);
8.15—8.23 (m, 3 H, H(9)—H(11)); 8.74 (d, 1 H, H(6), J = 8.2 Hz).
Found (%): C, 76.15; H, 5.28; N, 6.03; O, 12.54. C27H20N2O3.
Calculated (%): C, 77.14; H, 4.76; N, 6.67; O, 11.43.
4ꢀ(4ꢀBromostyryl)ꢀ2ꢀ(pꢀtolyl)pyrrolo[3,4ꢀc]quinolineꢀ1,3ꢀ
dione (9c). Light yellow crystals. The yield was 73%, m.p. 246 °C.
1H NMR (CDCl3), δ: 2.47 (s, 3 H, H(1)); 7.38 (s, 4 H,
H(2)—H(5)); 7.55 (d, 2 H, H(12), H(13), J = 8.5 Hz); 7.62
(d, 2 H, H(14), H(15), J = 8.5 Hz); 7.74 (t, 1 H, H(7), J = 7.7 Hz);
7.93 (t, 1 H, H(8), J = 7.7 Hz); 8.22 (m, 2 H, H(9), H(11)); 8.38
(d, 1 H, H(10), J = 15.8 Hz); 8.87 (d, 1 H, H(6), J = 8.3 Hz).
Found (%): C, 65.44; H, 4.13; N, 5.77; O, 7.87. C26H17N2O2Br.
Calculated (%): C, 66.52; H, 3.62; N, 5.97; O, 6.82.
4ꢀStyrylꢀ2ꢀ(pꢀtolyl)pyrrolo[3,4ꢀc]quinolineꢀ1,3ꢀdione (9d).
Greenish yellow crystals. The yield was 56%, m.p. 250—252 °C.
1H NMR (CDCl3), δ: 2.47 (s, 3 H, H(1)); 7.28—7.45 (m, 7 H,
H(2)—H(5), H(14), H(15), H(16)); 7.70 (t, 1 H, H(7), J = 7.2 Hz);
7.76 (d, 2 H, H(12), H(13), J = 7.2 Hz); 7.91 (t, 1 H, H(8),
J = 7.2 Hz); 8.21 (d, 1 H, H(9), J = 8.7 Hz); 8.28 (d, 1 H, H(11),
J = 15.9 Hz); 8.38 (d, 1 H, H(10), J = 15.7 Hz); 8.84 (d, 1 H, H(6),
J = 8.3 Hz). Found (%): C, 79.22; H, 5.16; N, 6.93; O, 8.69.
C26H18N2O2. Calculated (%): C, 80.00; H, 4.62; N, 7.18; O, 8.20.
Poly[(styrene)ꢀcoꢀ(4ꢀaminostyrene)ꢀcoꢀ(4ꢀ(4ꢀ(4ꢀdimethylꢀ
aminostyryl)ꢀ1,3ꢀdioxoꢀ1,3ꢀdihydropyrrolo[3,4ꢀc]quinolinꢀ2ꢀ
yl)styrene)] (7a). The yield was 47%. 1H NMR (CDCl3), δ: 1.53
(br.s 2 H, H(1)); 1.92 (br.s 1 H, H(2)), 2.91 (br.s 6 H, NMe2);
6.25—7.25 (br.m, 4 H, H(3)—H(6)); 7.31—8.89 (br.m, 10 H,
H(9)—H(12), H(14), H(15), H(1´)—H(4´)).
Poly[(styrene)ꢀcoꢀ(4ꢀaminostyrene)ꢀcoꢀ(4ꢀ(4ꢀ(4ꢀmethoxyꢀ
styryl)ꢀ1,3ꢀdioxoꢀ1,3ꢀdihydropyrrolo[3,4ꢀc]quinolinꢀ2ꢀyl)styrꢀ
ene)] (7b). The yield was 62%. 1H NMR (CDCl3), δ: 1.53 (br.s 2 H,
H(1)); 1.92 (br.s 1 H, H(2)); 3.76 (br.s 3 H, OMe); 6.25—7.25
(br.m, 6 H, H(3)—H(6), H(1´), H(3´)); 7.31—8.89 (br.m, 8 H,
H(9)—H(12), H(14), H(15), H(2´), H(4´)).
Poly[(styrene)ꢀcoꢀ(4ꢀaminostyrene)ꢀcoꢀ(4ꢀ(4ꢀ(4ꢀbromostyrꢀ
yl)ꢀ1,3ꢀdioxoꢀ1,3ꢀdihydropyrrolo[3,4ꢀc]quinolinꢀ2ꢀyl)styrene)]
1
(7c). The yield was 49%. H NMR (CDCl3), δ: 1.53 (br.s 2 H,
H(1)); 1.92 (br.s 1 H, H(2)); 6.25—7.25 (br.m, 4 H, H(3)—H(6));
7.31—8.89 (br.m, 10 H, H(9)—H(12), H(14), H(15),
H(1´)—H(4´)).
Poly[(styrene)ꢀcoꢀ(4ꢀaminostyrene)ꢀcoꢀ(4ꢀ(1,3ꢀdioxoꢀ4ꢀ
styrylꢀ1,3ꢀdihydropyrrolo[3,4ꢀc]quinolinꢀ2ꢀyl)styrene)] (7d). The
yield was 53%. 1H NMR (CDCl3), δ: 1.53 (br.s 2 H, H(1));
1.92 (br.s 1 H, H(2)); 6.25—7.45 (br.m, 6 H, H(3)—H(6),
H(1´)—H(3´)); 7.45—8.89 (br.m, 9 H, H(9)—H(12), H(14),
H(15), H (2´), H(4´), H(5´)).
4ꢀMethylꢀ2ꢀ(4ꢀmethylphenyl)pyrrolo[3,4ꢀc]quinolineꢀ1,3ꢀdiꢀ
one (8). A solution of anhydride 5 (2.24 g, 0.01 mol) in DMF
(20 mL) (preꢀprepared by stirring on a magnetic stirrer over 1 h)
was added to a solution of pꢀtoluidine (1.125 g, 0.01 mol) in
DMF (8.5 mL) cooled to –5 °C with stirring in the flow of arꢀ
gon, maintaining temperature below 10 °C. The reaction mixꢀ
ture was stirred for 1 h at 5 °C, then for 6 h at room temperature,
and kept for 10 h. Pyridine (0.55 mL) and acetic anhydride
(1.1 mL) were added to the reaction mixture, which was refluxed
for 6 h, excess of the solvent was evaporated in vacuo. A precipiꢀ
tate that formed was filtered off, washed with EtOH, and dried.
Recrystallization from the 1,4ꢀdioxane—water solvent mixture
yielded compound 8 (2.0 g, 63%) as light yellow crystals, m.p.
The authors are grateful to Marietta Böhm, Dipl.ꢀIng.,
University of Bayreuth (Germany), Chair of Macromoꢀ
lecular Chemistry 2, for the study of copolymers by GPC.
This work was financially supported by the Russian
Foundation for Basic Research (Project Nos 09ꢀ03ꢀ00408ꢀa
and № 09ꢀ03ꢀ12173ꢀofi_m).
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188 °C. H NMR (CDCl3), δ: 2.45 (s, 3 H, H(1)); 3.1 (s, 3 H,
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Received April 20, 2010;
in revised form November 16, 2010