Polymeric malondialdehyde dianils - A novel type of electrically conducting polymers

Article abstract of DOI:10.1039/a801654b

The reaction of vinamidinium salts with para-substituted aromatic diamines gives rise to polymeric 2-aryl malonaldehyde dianils in good yields. Polymeric cyanines can be obtained from tetramethoxypropane and a pentamethine cyanine, respectively, and para-substituted aromatic diamines. The degree of polymerisation P_n (n=10-40) was estimated by measuring the intrinsic viscosity η. The polymers show high electrical powder conductivities (σ=0.03-50 S cm^-1) after doping with iodine or FeCl₃.

Full text of DOI:10.1039/a801654b

J O U R N A L O F
Polymeric malondialdehyde dianils—a novel type of electrically
conducting polymers
Rudolf Gompper,* Thomas J. J. Mu¨ller* and Kurt Polborn
Institut fur Organische Chemie der Universitat Munchen, Karlstr. 23, D-80333 Munchen,
¨
¨
¨
¨
C H E M I S T R Y
Germany
The reaction of vinamidinium salts with para-substituted aromatic diamines gives rise to polymeric 2-aryl malonaldehyde dianils
in good yields. Polymeric cyanines can be obtained from tetramethoxypropane and a pentamethine cyanine, respectively, and
para-substituted aromatic diamines. The degree of polymerisation P (n=10–40) was estimated by measuring the intrinsic
n
viscosity g. The polymers show high electrical powder conductivities (s=0.03–50 S cm−1) after doping with iodine or FeCl .
3
The electrical conductivity of polymers1 such as polyacetylene,2
polyaniline3 1, poly-p-phenylene4 and polythiophene5 is based
on a conjugated p-electron system.6 In their native or undoped
state, however, these polymers exhibit only a low electrical
conductivity which is due to a rather large energy band gap
caused by Peierls distortion.7 Only by doping—oxidatively or
reductively—can they be converted into ‘organic metals’.8
R
H
H
N
N
+
N
N
H
n
3
n
4
H
H
N
N
+
N
+
+
N
+
N
N
n
1ox
H
H
1
R
+
NR2
R2N
n
N
N
2
N
N
Cyanine dyes 2 have relatively small HOMO–LUMO gaps,9
double-bond delocalization9 and they are easily polarizable.9,10
Thus, since cyanine dyes fulfill essential requirements for
‘synthetic metals’10 we set out to synthesize arylene-bridged
polymeric vinamidinium salts 3 and vinamidines 4.11 These
compounds combine the structural features of polyaniline 1,
polyarylenes, polyarylenevinylenes and cyanine dyes 2. The
fully oxidized form 4ox of 4 is an azabutadienediyl homologue
of deprotonated 1. In particular, polyvinamidines 4 with func-
tional groups R in position 2 could be of interest as model
compounds for molecular electronic devices.12
R
n
4ox
expected to cause the opposite effect. Unexpectedly, the pyridi-
nio group in 6c does not exert a distinct hypsochromic shift.
This can be rationalized on the basis of the cis–trans isomer-
ism17 of vinamidines. In less polar solvents and in the solid
state the cis, cis structure (‘horseshoe-form’) is thermo-
dynamically favoured.17 The contribution of the all-trans struc-
ture (‘W-form’) increases with increasing polarity of solvents
(e.g. DMSO).17 The equilibrium between horseshoe- and W-
forms of 6 is responsible for the broad absorption bands in
the electronic spectra. Apparently, the cationic pyridinio group
of 6c stabilizes the all-trans structure of the vinamidine system
presumably by an enhanced aggregation of DMSO molecules.
In addition, in all-trans structures of vinamidines, aryl substitu-
ents in position 2 are orthogonally arranged and have therefore
no mesomeric effect on the p–p* transition of cyanines.19
Results and Discussion
Synthesis and structural aspects of 2-arylmalonaldehyde dianils
Although malonaldehyde dianil 6, R1, R2=H,13 and its metal
complexes14 have been known for a long time, 2-arylmalonal-
dehyde dianils have not been investigated that much (cf. NMR
properties of highly substituted vinamidines and their nickel
chelates15). We have now synthesized a range of malonaldehyde
dianils 6 as models for polymers 4 by reacting 2-arylvinamidin-
ium salts 516 with primary aromatic amines (Scheme 1). The
electronic spectra of 6a and 6e show longest wavelength
absorption maxima at 398 and 408 nm, respectively, which are
In the spectra of 6b (l =450 nm [in DMSO]), 6d (l
403 nm) and 6f (l =452 nm) the longest wavelength absorp-
tion maxima are shifted bathochromically compared with l
=
max
max
red-shifted compared with l
of 6, R1, R2=H, at 360 nm.17
max
max
This is consistent with PMO theory18 predicting a red shift of
the p–p* transition by donor substituents at an even-numbered
position in a cyanine system. An acceptor substituent is
max
of 6a due to the extended p-electron system (R2=H vs.
R2=NMe ).
2
J. Mater. Chem., 1998, 8(9), 2011–2018
2011

NH bond lengths are caused by nonstoichiometric amounts of
methanol molecules included in the crystal. These molecules
bring about a stronger perturbation of the NH···N bond in
molecule 1 than in molecule 2. The bond lengths in the
trimethine imine systems are affected as well. The terminal
phenyl rings are only slightly twisted out of the plane of the
trimethine system (Fig. 2) so that a maximum overlap of the
p-orbitals can be expected in the solid state. The p-methoxy-
phenyl substituent is twisted by 44.16° (molecule 1) and 46.72°
(molecule 2) with respect to the cyanine system (Fig. 2). The
horseshoe shape is characteristic for solid state structures of
vinamidines bearing aryl substituents in position 2 (cf. the
dianil of acetylacetone20).
Synthesis of polymeric arylene-bridged cyanines and
vinamidines
Dark red polymeric vinamidines 7 are readily obtained when
vinamidinium salts 5 are refluxed with equimolar amounts of
p-phenylenediamine (7a,d–f ), benzidine (7b) or 4,4∞-diamino-
stilbene (7c,g) in ethanol, diglyme or methanol in the pres-
ence of catalytic amounts of acetic acid. A model of the
structure of polymers 7a–e is displayed in Scheme 2.
The comparision of the IR data of 6 and 7 reveals that these
compounds have similar structural features (horseshoe-shape
of the trimethine imine moieties).
All polymers are air and water stable. Solutions of those
polymers that are soluble in chloroform were used to form
thin films on glass plates.
The degree of polymerisation and the chain length of 7 can
be estimated by determining the average molecular weight by
measuring the intrinsic viscosity g (Table 1) of the soluble
polymers (7a–c) in trichloromethane (polystyrene standard).22
Scheme 1
Crystal structure of 6e
Compound 6e is a model for a segment of the polymers 7.
Therefore, a crystal structure analysis of 6a would help to
understand the properties of 7.
The unit cell of a crystal of 6e consists of eight molecules.
There are two independent types of molecules (molecules 1
and 2), both exhibiting a horseshoe-shaped trimethine imine
system (Fig. 1). These two molecules are different in some
aspects. The differences in the dihedral angles as well as in the
Fig. 2 ORTEP plot of molecule
C(2A)–C(10A) bond.
2
of 6e, view down the
Fig. 1 Structure of 6e in the crystal (ORTEP plots of two independent molecules).21 Selected bond lengths (pm) and bond angles (°): Molecule
1: N1–C1 135.3(4), C1–C2 137.2(5), C2–C3 142.1(5), C3–N2 129.1(4), C2–C10 148.7(5), N1–C4 139.9(4), N2–C17 141.2(5), N1–H 90.4, N2–H
206.6; N1–C1–C2 124.4(3), C1–C2–C3 122.1(3), C2–C3–N2 125.5(3), N1–H–N2 129.64. Molecule 2: N1A–C1A 132.5(5), C1A–C2A 138.1(6),
C2A–C3A 142.9(5), C3A–N2A 130.3(5), C2A–C10A 146.7(5), N1A–C4A 139.7(5), N2A–C17A 140.7(4), N1A–H(A) 168.8, N2A–H(A) 109.5;
N1A–C1A–C2A 125.9(4), C1A–C2A–C3A 119.5(3), C2A–C3A–N2A 126.0(4), N1A–H(A)–N2A 150.31.
2012
J. Mater. Chem., 1998, 8(9), 2011–2018

dl g−1) reveal that the polymeric vinamidines 7 have a high
degree P of polymerisation.
n
N1,N2-Diarylvinamidinium salts such as 8 can be obtained
by reacting tetramethoxypropane with primary and secondary
aromatic amines in the presence of perchloric acid
(Scheme 3).23 By performing this reaction with para-substituted
aromatic diamines in the presence of tetrafluoroboric acid,
polymeric arylene-bridged cyanines 9 can be prepared. In the
same way, the condensation of the pentamethinium salt 1024
with para-substituted aromatic diamines yields the polymers
11.
Scheme 2
R1
H
R1
N
N
N
N
Ar
H
Ar
H
Ar
H
Ar
N
N
N
N
R1
R1
n
Model of the structures of polymeric vinamidines 7a–e
Table 1 22 Intrinsic viscosities g, molecular weight M of the polymer,
molecular weight M of the repeating unit and degree P of polymeris-
ation of 7a–c
n
m
n
g/dl g−1
0.8
0.4
0.6
M g mol−1
17000
8000
15000
M /g mol−1
P
n
m
n
7a
7b
7c
404.6
480.7
506.7
42
17
30
Scheme 3
The degrees of polymerisation P of 9 (n=8, 11) (Table 2)
are lower than those of 7a–c (n=42, 17, 30) (Table 1).
Obviously, the condensation leading to 9 is terminated by
precipitation of the polycationic polymeric cyanines. The poly-
mers 9 and 11 have similar spectroscopic properties to those
n
The average degree P of polymerisation is defined by P =
M /M , where M is the molecular weight as determined by
n
n
n
m
n
the intrinsic viscosity g and M is the molar weight of the
repeating unit of the polymer. The high values of g (0.4–0.8
m
J. Mater. Chem., 1998, 8(9), 2011–2018
2013

Table 2 22 Intrinsic viscosities g, molecular weight M of the polymer,
molecular weight M of the repeating unit and degree P of polymeris-
ation of 9a,c
n
m
n
g/dl g−1
0.1
0.1
M /g mol−1
2500
2500
M /g mol−1
232.0
334.1
P
n
m
n
9a
9c
11
8
of 8. Compared with 8, a bathochromic shift of the longest
wavelength absorption maxima in the electronic spectra of 9
(9a: l =499 nm, 9b: l =461nm, 9c: l =492 nm) and
max
max
max
11 (11a: l =595 nm, 11a: l =541 nm) is observed indicat-
max
max
ing rather strong intramolecular electronic interaction between
the cyanine systems in the polymer chains.
In order to obtain polymers of the type 4ox, 7c was treated
with sodium chromate in trifluoroacetic acid25 or with tetra-
fluoroboric acid in ether in the presence of air (Scheme 4). The
products 12a and 12b were identical according to their IR
(KBr) and UV–VIS (DMSO) spectra (12a: l =470 nm,
max
n
=1614 cm−1; 12b: l
(log e)=470 nm (4.509), n
=
˜
˜
N
N
N
C
N
max
C
Scheme 4
1614 cm−1).
The ESR spectrum of 12a reveals that there is a significant
contribution of unpaired spins (Fig. 3). The ESR spectrum
(Fig. 4) of a sample of 7c doped with iodine26 is very similar
to that of 12a showing that unpaired spins are generated upon
doping. Apparently, the electronic structures of 12a and 7c(ox)
are closely related.
Table 3 Powder conductivities s of undoped and doped polymeric
vinamidines 7 and cyanines 9, 11 and 12
s/S cm−1
s/S cm−1
undoped
doped
undoped
doped
Electrical conductivities22
7a
7b
7c
7d
7e
7f
10−5
0.8
17
30
0.35
0.2
0.4
50
9a
9b
9c
11a
11b
12a
12b
3×10−2
2.5×10−2
0.1
—
10
—
35
20
35
30
10−4
The electrical powder conductivities22,26 (Table 3) of pellets of
native and doped26 (with iodine or ferric chloride) 7, 9, 11 and
12, measured at room temperature and ambient pressure, are
remarkably high even in the native state. While the conductivit-
ies of undoped 7 are close to those of semiconductors, those
of the polymeric salts 7f, 7g, 9, 11 and 12 are distinctly higher.
The conductivities of the undoped bipyridinediio-bridged poly-
meric vinamidines 7f and 7g are similar to the conductivity of
the polymeric viologen derivative 13 (10−3 S cm−1).27
10−4
5×10−3
4×10−3
2.5×10−3
4.8×10−2
0.15
4.5×10−2
6×10−2
2×10−2
7g
Apparently, in 7f,g a charge transfer from the vinamidine
moieties to the bipyridinediio moieties takes place which
amounts to a self-p-doping of the polymer.
+
+
N
N
Br–/Cl–
n
13
The resonance stabilization of positive charges in the poly-
meric cyanines 9, 11 and 12 seems to suppress the Peierls
distortion7 locally. According to Dahne28 the electrical conduc-
¨
tivity of cyanines is caused by the aggregation of cations and
anions in one- and two-dimensional rods. The electrical con-
ductivities of polymers 7, 9, 11 and 12 increase upon doping
by two to six orders of magnitude (0.03–50 S cm−1). The
observed values are in the same order of magnitude as those
of polyaniline (5 S cm−1).3
Fig. 3 ESR spectrum of 12a: g=2.0048 (sweep: 400 G, standard signal
[MnO]: g =2.0336 and g =1.9809)
3
4
Conclusion
Polymeric cyanines and vinamidines are a novel type of
electrically conducting polymers, are readily accessible and
feature high electrical conductivities after doping. They com-
bine the electronic properties of cyanines and vinamidines with
those of polyarylenevinylenes and polyaniline.
This work has been supported by the Deutsche
Forschungsgemeinschaft (DFG) and the Fonds der
Chemischen Industrie. T. J. J. M. thanks the Freistaat Bayern
for a Promotionsstipendium. We thank the BASF AG for the
Fig. 4 ESR spectrum of 7c doped with iodine: g=2.0048 (sweep: 400 G;
standard signal [MnO]: g =2.0336 and g =1.9808)
3
4
2014
J. Mater. Chem., 1998, 8(9), 2011–2018

donation of chemicals and particularly Dr H. Naarmann
(BASF AG, Ludwigshafen) for measuring inherent viscosities
and electrical conductivities.
cooling and adding water (10 ml) a lemon-colored solid pre-
cipitated. The precipitate was collected by suction filtration,
washed with water, and recrystallized (EtOH). Yield, 0.30 g
(50%); lemon-colored platelets; mp 126–128 °C. IR (KBr):
n˜/cm−1=1640, 1594, 1544, 1294, 757, 695. UV–VIS (DMSO):
Experimental
l
/nm (log e)=292 (4.260), 398 (4.241); 1H NMR (400 MHz,
max
The 1H NMR spectra were recorded on Bruker WP 80
(80 MHz), Varian VXR 400 S (400 MHz) and JEOL EX-400
(400 MHz) spectrometers. The 13C NMR spectra were recorded
CDCl ): d=7.08–7.39 (m, 15 H, phenyl-H), 8.06 (s, 2 H,
3
NCHC); 13C NMR (CDCl ): d=109.58 (s, C-2), 118.37 (d, C-
4), 123.81 (d, C-6), 125.56, 126.05, 128.75, 129.42 (d, C-5),
3
on Varian VXR 400
S (100 MHz) and JEOL EX-400
140.22, 146.47 (s, C-3), 149.22 (d, C-1). Found C, 84.34; H,
5.92; N, 9.38%. Calc. for: C H N (298.4) C 84.53 H 6.08 N
9.39%.
(100 MHz) spectrometers. All NMR spectra were recorded
with tetramethylsilane (TMS) as internal standard. Intrinsic
viscosities were determined in chloroform (with polystyrene as
internal standard) with the Mark–Houwink–Sakurada param-
eters k=0.21×105 dl g−1 and a=0.94. The ESR spectra were
recorded on a Varian E-Line (9.28 GHz) spectrometer with
MnO as internal standard. The IR spectra were recorded on
Perkin-Elmer 125 and Bruker IFS 145 spectrometers and the
UV–VIS spectra on Zeiss DMR 10 and Perkin-Elmer Lambda
3 spectrometers. The pellets for measuring the electrical con-
ductivities were prepared at 300 bar pressure.21 The crystal
structure analysis was performed on a ENRAF-NONIUS
CAD4 single crystal diffractometer. The melting points are not
corrected. Solvents were dried by standard methods, products
in vacuo (10−2 torr) at 60–80 °C. Ether refers to diethyl ether.
All chemicals were commercially available or prepared by
literature procedures. Carcinogenic chemicals such as benzidine
should be handled with special care and only in a fume hood.
21 18
2
3-( p-Dimethylaminophenylamino)-2-phenyl-N-( p-dimethyl-
aminophenyl )-prop-2-enimine 6b
A suspension of 5a29 (0.45 g, 1.49 mmol) and N,N-dimethyl-p-
phenylenediamine (0.27 g, 2.96 mmol) in MeOH (20 ml) was
refluxed for 1 h. After cooling and adding water (20 ml) an
orange solid precipitated. The aqueous solution and the pre-
cipitate were extracted with dichloromethane. The organic
phase was dried over anhydrous sodium sulfate. The solvent
was removed in vacuo at 25 °C and the residue recrystallized
(MeOH). Yield, 0.13 g (23%), orange needles; mp 91–92 °C.
IR (KBr): n˜/cm−1=1637, 1608, 1544, 1512, 1294, 1219, 1165,
816, 761, 700; UV–VIS (DMSO): l /nm (log e)=245 (4.220),
max
317 (4.370), 450 (4.430); 1H NMR (80 MHz, CDCl ): d=2.91
3
(s, 12 H, NCH ), 6.64–7.35 (m, 13 H, phenyl-H, phenylene-H),
3
7.95 (s, 2 H, NCHC). Calc. for C H N (384.5): C, 78.09; H,
25 28
4
7.34; N, 14.57%. Found C, 78.36; H, 7.11; N, 14.03%.
p-(Dodecyloxy)phenylacetic acid
p-Hydroxyphenylacetic acid (9.13 g, 60.0 mmol), dodecyl bro-
mide (16.45 g, 66.0 mmol) and potassium hydroxide (6.73 g,
120 mmol) in ethanol (50 ml) were refluxed for 20 h. After
cooling, potassium hydroxide (3.37 g, 60.0 mmol) was added,
the mixture refluxed for 2 h and after cooling acidified with
2  HCl. After adding water (100 ml), the precipitate was
suction filtered and extracted with diethyl ether. The ether
phase was dried with anhydrous magnesium sulfate. The
solvent was removed in vacuo at 25 °C. Yield, 15.82 g (82%);
2-(1-Pyridinio)-3-( p-tert-butylphenylamino)-N-( p-tert-
butylphenyl)prop-2-enimine tetrafluoroborate 6c
A suspension of 5b30 (0.76 g, 2.00 mmol) and p-tert-butylaniline
(0.60 g, 4.07 mmol) in MeOH (10 ml) was refluxed for 3.5 h.
After cooling, the solvent was removed partially in vacuo at
50 °C. The precipitate was collected by suction filtration,
washed with diethyl ether, and recrystallized (MeOH). Yield,
0.71 g (71%), yellow quadratic plates; mp 241–242 °C
(decomp.). IR (KBr): n/cm−1=1658, 1587, 1521, 1471, 1364,
˜
colourless flakes; mp 78–79 °C. 1H NMR (80 MHz, CDCl ):
3
d=0.86–1.80 (m, br, 23 H, alkyl-H), 3.48 (s, 2 H, aryl-CH -
2
1310, 1267, 1084, 836; UV–VIS (DMSO): l /nm (log e)=
max
250 (4.190), 297 (3.978), 357 (4.540); 1H NMR (400 MHz,
CO H), 3.85 (t, 2 H, aryl-OCH -alkyl), 6.47–7.07 (AA∞BB∞, J
2
2
[D ]DMSO): d=1.33 (s, 18 H, (CH ) C), 6.94–7.41 (m, 8 H,
phenylene-H), 7.90 (s, 1 H, NCHC), 8.15–9.19 (m, 5 H,
9.6 Hz, 4 H, phenylene-H), 10.24 (s, br, 1 H, CO H). Calc. for
C H O (320.5): C, 74.96; H, 10.06%. Found: C, 75.52;
H, 10.25%.
6
3 3
2
20 32
3
pyridinio-H). Calc. for C H BF N (499.9): C, 67.34; H, 6.86;
N, 8.41%. Found: C, 67.21; H, 6.87; N, 8.36%.
28 34
4 3
3-Dimethylamino-2-[p-(dodecyloxy)phenyl]-N,N-dimethyl-
prop-2-eniminium perchlorate 5d
2-(1-Pyridinio)-3-( p-dimethylaminophenylamino)-N-( p-
dimethyaminophenyl )prop-2-enimine tetrafluoroborate 6d
p-(Dodecyloxy)phenylacetic acid (3.54 g, 11.0 mmol) was
added in small portions at 0 °C to Vilsmeier’s reagent prepared
from dimethylformamide (4.25 ml, 55.0 mmol) and phosphoryl
chloride (3 ml, 33.0 mmol). The mixture was heated to
80–90 °C for 13 h. After cooling, the mixture was poured into
ice–water (50 ml) and sodium perchlorate (1.50 g, 12.2 mmol)
was added under stirring. The precipitate was collected by
suction filtration and washed with water and ether. Yield,
4.02 g (75%); colourless powder; mp 101–102 °C. IR (KBr):
n˜/cm−1=2922, 2854, 1610, 1585, 1521, 1418, 1400, 1289, 1248,
A suspension of 5b30 (1.52 g, 4.01 mmol) and N,N-dimethyl-p-
phenylenediamine (1.10 g, 8.08 mmol) in MeOH (10 ml) was
refluxed for 6 h. After cooling, the solvent was removed in
vacuo at 50 °C, the residue was stirred with hot EtOH, immedi-
ately collected by suction filtration, and recrystallized (aceto-
nitrile–ether). Yield, 0.70 g (38%), dark red crystals; mp 192 °C.
IR (KBr): n/cm−1=1656, 1522, 1084, 946, 821; UV–VIS
˜
(DMSO): l /nm (log e)=263 (4.299), 336 (4.220), 403
max
(4.520); 1H NMR (400 MHz, [D ]DMSO): d=2.81 (s, 12 H,
NCH ), 6.65–7.25 (m, 8 H, phenylene-H), 8.14–9.13 (m, 7 H,
6
1109, 1092, 815, 785, 624; UV–VIS (DMSO): l /nm (log e)=
3
max
319 (4.614); 1H NMR (80 MHz, CDCl ): d=0.88–1.85 (s, 23
3
NCHC, pyridinio-H); 13C NMR (100 MHz, [D ]DMSO): d=
6
40.93 (q, NCH ), 113.03 (d, C-5), 119.88 (d, C-4), 122.47 (s, C-
3
H, alkyl-H), 2.50 (s, 6 H, NCH ), 3.29 (s, 6 H, NCH ), 3.92 (t,
3
3
2), 128.73, 134.56 (s, C-3), 145.78 (d, C-1), 146.47, 148.34 (s, C-
2 H, aryl-OCH -alkyl), 6.83–7.10 (AA∞BB∞, J 8.0 Hz, 4 H,
phenylene-H), 7.73 (s, 2 H, NCHC). Calc. for C H ClN O
2
6), 148.39. Calc. for C H BF N (473.3): C, 60.90; H, 5.96;
N, 14.80%. Found: C, 60.73; H, 6.12; N, 14.84%.
24 28
4 5
25 43
2 5
(487.1): C, 61.65; H, 8.90; N, 5.75%. Found: C, 61.58; H, 8.83;
N, 5.67%.
2-( p-Methoxyphenyl)-3-phenylamino-N-phenylprop-2-enimine
6e
2-Phenyl-3-anilino-N-phenylprop-2-enimine 6a
A suspension of 5a29 (0.60 g, 1.98 mmol) and aniline (0.39 g,
4.28 mmol) in MeOH (10 ml) was refluxed for 3.5 h. After
A suspension of 5c30 (0.66 g, 1.98 mmol), aniline (0.39 g,
4.19 mmol), and triethylamine (0.62 ml, 4.28 mmol) in EtOH
J. Mater. Chem., 1998, 8(9), 2011–2018
2015

(10 ml) was refluxed for 12 h. After cooling, water (20 ml) was
added and the mixture was extracted with dichloromethane.
The organic phase was dried with anhydrous sodium sulfate,
the solvent was removed in vacuo at 25 °C, and the residue
was recrystallized (MeOH). Yield, 0.14 g (21%), yellow needles;
mp 102–103 °C. IR (KBr): n˜/cm−1=1641, 1598, 1545, 1502,
1292, 1242, 832, 761, 752, 690; UV–VIS (CHCl ): l /nm
powder with a greenish lustre; mp 165–166 °C. IR (KBr):
n/cm−1=2922, 2851, 1639, 1608, 1536, 1513, 1283, 1241, 1210,
˜
1175, 816; UV–VIS (CHCl ): l /nm (log e)=278 (4.241),
3
max
448 (4.620); (CF CO H): l /nm (log e)=261 (4.352), 441
max
(4.731). Calc. for (C H N OΩ0.25 H O) [(485.2) ]: C, 81.69;
3
2
33 40
2
2
n
n
H, 8.41; N 5.77%. Found: C, 81.68; H, 8.31; N, 5.56%.
3
max
(log e)=251 (4.248), 398 (4.494), 445 (sh, 4.303); (HCO H):
2
Poly[3-amino-2-(p-dodecyloxyphenyl)prop-2-eniminyl(p-
phenylenevinylphenylene)] 7c
l
/nm (log e)=384 nm (5.084); 1H NMR (400 MHz,
max
CDCl ): d=3.83 (s, 3 H, OCH ), 6.92–7.37 (m, AA∞BB∞,
3
3
J 8.7 Hz, 14 H, phenyl-H, phenylene-H), 8.01 (s, br, 2 H,
NCHC); 13C NMR (100 MHz, CDCl ): d=55.41 (q, OCH ),
109.46 (s, C-2), 114.38, 118.33 (d, C-4), 127.85 (d, C-6), 129.45
As described for 7a with 5d (0.95 g, 2.00 mmol) and 4,4∞-
diaminostilbene (0.42 g, 2.00 mmol). Yield, 0.62 g (60%),
brown-red powder with a greenish lustre; mp 156–157 °C. IR
3
3
(d, C-5), 129.80, 133.11, 146.37 (s, C-3), 149.00 (d, C-1), 158.41.
(336.4): C, 79.44; H, 6.29;
(KBr): n/cm−1=2922, 2851, 1639, 1606, 1538, 1511, 1286, 1243,
˜
Calc. for C H N OΩ25 CH OH
N, 8.33%. Found: C, 79.35; H, 6.17; N 8.34%.
1177, 1027, 827; UV–VIS (CHCl ): l /nm (log e)=310
22 20
2
3
0.25
3
max
(4.260), 473 (4.620); (CF CO H): l /nm=296, 458. Calc. for
max
(C H N OΩ0.5 H O) [(515.7) ]: C, 81.52; H, 8.40; N, 5.43%.
Found; C, 81.66; H, 8.18; N 5.71%.
3
2
35 42
2
2
n
n
3-(p-Dimethylaminophenylamino)-2-(p-methoxyphenyl)-N-(p-
dimethylaminophenyl)prop-2-enimine 6f
A suspension of 5c30 (0.66 g, 1.98 mmol), N,N-dimethyl-p-
phenylenediamine (0.54 g, 3.96 mmol), and triethylamine
(0.78 ml, 5.38 mmol) in EtOH (10 ml) was refluxed for 12 h.
After cooling, water (20 ml) was added and the mixture was
extracted with dichloromethane. The organic phase was dried
over anhydrous sodium sulfate and the solvent was removed
in vacuo at 25 °C. The residue was dissolved in diethyl ether,
the solution filtered over silica gel, dried with anhydrous
magnesium sulfate and the solvent was evaporated at room
temperature. Yield, 0.12 g (14%), yellow brownish powder; mp
Poly[3-amino-2-(1-pyridinio)prop-2-eniminyl(p-phenylene)
tetrafluoroborate] 7d
The suspension of 5b30 (0.76 g, 2.01 mmol) and p-phenylenedi-
amine (0.22 g, 2.04 mmol) in a mixture of diglyme (18 ml) and
AcOH (2 ml) was heated to 120 °C for 3.5 h. After cooling, the
precipitate was suction filtered and washed with MeOH and
ether. Yield, 0.56 g (91%), dark red powder; mp 296 °C. IR
(KBr): n˜/cm−1=1646, 1516, 1301, 1084, 827, 774, 681, 520;
UV–VIS (DMSO): l /nm (log e)=256 (4.111), 453 (4.369).
max
147–148 °C. IR (KBr): n/cm−1=1636, 1608, 1542, 1512, 1293,
˜
Calc. for (C H BF N Ω0.4 H O) [(316.3) ]: C, 53.17; H,
4.08; N, 13.29%. Found: C, 53.36; H, 4.38; N, 13.10%.
14 12
4
3
2
n
n
847; UV–VIS (DMSO): l /nm (log e)=307 (4.396), 452
max
(4.436); (HCO H): l /nm (log e)=385 (4.763), 499 (3.123);
2
max
1H NMR (400 MHz, CDCl ): d=2.93 (s, 12 H, NCH ), 3.83
3
3
Poly[3-amino-2-(4-dimethylamino-1-pyridinio)prop-2-
eniminyl(p-phenylene) tetrafluoroborate] 7e
(s, 3 H, OCH ), 6.76–7.09 (AA∞BB∞, J 9.0 Hz, 8 H, phenylene-
3
H), 6.91–7.29 (AA∞BB∞, J 8.4 Hz, 4 H, phenylene-H), 7.93 (s, 2
H, NCHC); 13C NMR (100 MHz, CDCl ): d=41.15 (q, NCH ),
55.41 (q, OCH ), 108.10 (s, C-2), 113.92 (d, C-5), 114.15, 119.34
The suspension of 5e31 (0.84 g, 1.99 mmol) and p-phenylenedi-
amine (0.22 g, 2.04 mmol) in MeOH (20 ml) and AcOH (five
drops) was refluxed for 1 h. After cooling, the precipitate was
suction filtered (Schlenck funnel) and washed with acetic acid,
MeOH and ether. Yield, 0.54 g (71%), dark red powder; mp
280 °C (decomp.). IR (KBr): n˜/cm−1=1647, 1608, 1575, 1516,
1403, 1289, 1190, 1123, 1084, 825, 522; UV–VIS (DMSO):
3
3
3
(d, C-4), 127.22, 133.76, 137.27 (s, C-3), 147.39 (d, C-1), 147.75
(s, C-6), 157.64. Calc. for C H N O (414.6): C, 75.33; H, 7.29;
N, 13.52%. Found: C, 74.83; H, 7.26; N, 13.27%.
26 30
4
Poly[3-amino-2-(p-dodecyloxyphenyl)prop-2-eniminyl(p-
phenylene)] 7a
l
/nm (log e)=292 (4.361), 440 (4.439). Calc. for
max
(C H BF N Ω1.5 H O) [(379.2) ]: C, 50.68; H, 5.32; N,
14.78%. Found: C, 50.80; H, 5.07; N 15.73%.
The solution of 5d (2.85 g, 6.01 mmol), p-phenylenediamine
(0.66 g, 6.11 mmol), and five drops of AcOH in EtOH (15 ml)
was refluxed for 15 h. After cooling, the precipitate was col-
lected by suction filtration and washed with EtOH, then with
a 151 mixture of EtOH and triethylamine, and finally with
EtOH. After triturating with ether, the residue was collected
by filtration. Yield, 1.11 g (45%), dark red powder with a
greenish lustre; mp 199–200 °C. IR (KBr): n˜/cm−1=2924, 2853,
16 17
4
4
2
n
n
Poly{2,2∞-(4,4∞-bipyridine-1,1∞-diylium)di[3-aminoprop-2-
eniminyl(p-phenylene)] bis(tetrafluoroborate)} 7f
The suspension of 5f 31 (0.38 g, 0.50 mmol) and p-phenylenedi-
amine (0.12 g, 1.11 mmol) in MeOH (20 ml) and AcOH (five
drops) was refluxed for 9 h. After cooling, the precipitate was
suction filtered (Schlenck funnel) and washed with AcOH,
MeOH, a 151 mixture of MeOH and triethylamine, MeOH,
and ether. Yield, 0.28 g (100%), black powder; mp >350 °C.
IR (KBr): n˜/cm−1=1637, 1608, 1514, 1299, 1084, 833, 523.
Calc. for (C H B F N ΩC H N ΩCH OH) [(756.3) ]: C,
1637, 1606, 1538, 1508, 1279, 1243, 1027, 827; UV–VIS (CHCl ):
3
l
l
/nm (log e)=283 (4.210), 484 (4.210); (CF CO H):
max
max
3
2
/nm (log e)=465 (4.459). Calc. for (C H N OΩ0.5 H O)
[(413.6) ]: C, 78.41; H, 9.02; N, 6.77%. Found: C, 78.65; H,
27 36
2
2
n
n
8.89; N, 7.12%.
28 22 2 8
6
6
8
2
3
n
n
Poly[3-amino-2-(p-dodecyloxyphenyl)prop-2-eniminyl(p-
phenylphenylene)] 7b
55.58; H, 4.53; N, 14.82%. Found: C, 56.11; H, 4.67; N, 14.60%.
Triethylamine (0.30 ml, 2.07 mmol) and 5d (0.95 g, 2.00 mmol)
were added successively to a suspension of benzidine dihydro-
chloride (0.52 g, 2.02 mmol) in EtOH (10 ml). The mixture
was refluxed for 18 h. After cooling, the precipitate was suction
filtered and washed with EtOH, then with a 151 mixture of
EtOH and triethylamine, and finally with EtOH. The residue
was dissolved in chloroform and the solution was filtered. The
solvent was removed in vacuo at 50 °C, the residue was trituated
with ether and collected by filtration. Yield, 0.67 g (69%), red
Poly{2,2∞-(4,4∞-bipyridine-1,1∞-diylium)di[3-aminoprop-2-
eniminyl(p-phenylvinylphenylene)] bis(tetrafluoroborate)} 7g
As described for 10f with 8f31 (0.38 g, 0.50 mmol) and 4,4’-
diaminostilbene (0.22 g, 1.05 mmol). Yield, 0.35 g (77%), black
powder; mp >350 °C. IR (KBr): n˜/cm−1=1636, 1603, 1576,
1300, 1084, 1063, 964, 835, 522. Calc. for (C H B F N Ω0.5
44 34 2 8
6
CH OH) [(836.4) ]: C, 63.90; H, 4.34; N, 10.05%. Found: C,
64.15; H, 4.72; N, 12.00%.
3
n
n
2016
J. Mater. Chem., 1998, 8(9), 2011–2018

Poly[p-phenylene-3-aminoprop-2-eniminium tetrafluoroborate]
9a
(C H BrN Ω0.5 H O) [(362.3) ]: C, 62.99; H, 5.07; N, 7.73%.
Found: C, 62.95; H, 5.46; N, 8.53%.
19 17
2
2
n
n
1,1,3,3-Tetramethoxypropane (1.64 g, 9.99 mmol) and then
50% aqueous tetrafluoroboric acid (1 ml) were added under
stirring to a solution of p-phenylenediamine (1.08 g, 10.0 mmol)
in EtOH (10 ml). After 20 min, the mixture was refluxed for
9 h. After cooling, the precipitate was suction filtered and
stirred at room temperature with a mixture of 50% aqueous
tetrafluoroboric acid (10 ml) and EtOH (10 ml) for 1 h. The
precipitate was suction filtered and washed with EtOH and
ether. Yield, 1.04 g (46%), brown-red powder; mp 331–332 °C.
IR (KBr): n˜/cm−1=3003, 1615, 1585, 1505, 1324, 1275, 1192,
Oxidation of 7c with sodium dichromate (12a)
Sodium dichromate (0.18 g, 0.68 mmol) was added under
stirring at 0 °C to a mixture of AcOH (10 ml), Ac O (10 ml),
and 50% ethereal tetrafluoroboric acid (3 ml) prepared under
external ice cooling. The mixture was filtered and a solution
of 10c (0.26 g, 0.51 mmol) in trifluoroacetic acid (30 ml) was
added dropwise. The mixture was stirred overnight at room
temperature. The precipitate was suction filtered and washed
with AcOH and ether. Yield, 0.19 g (56%), red powder with a
2
1084, 835, 668, 532; UV–VIS (DMSO): l /nm (log e)=317
greenish lustre; mp 230 °C (decomp.). IR (KBr): n/cm−1=2922,
˜
2851, 1614, 1596, 1561, 1516, 1464, 1318, 1299, 1253, 1193,
max
(3.808), 499 (4.486). Calc. for (C H BF N Ω0.5 H O)
[(241.1) ]: C, 44.85; H, 4.18; N, 11.62%. Found: C, 44.22; H,
4.30; N, 12.07%.
9
9
4
2
2
n
1179, 1084, 833, 720, 533; UV–VIS (DMSO): l /nm=330,
n
max
470; ESR (solid state, MnO): g=2.0034. Calc. for
(C H B F N O) [(681.4) ]: C, 61.70; H, 6.36; N, 4.11%.
Found: C, 61.58; H, 6.52; N, 4.29%.
35 43 2 8
2
n
n
Poly[4,4∞-biphenylene-3-aminoprop-2-eniminium
tetrafluoroborate] 9b
Oxidation of 7c with air and HBF ( 12b)
4
1,1,3,3-Tetramethoxypropane (0.66 g, 4.02 mmol), triethyl-
amine (0.5 ml), and 50% aqueous tetrafluoroboric acid (1 ml)
were added successively under stirring to a supension of
benzidine hydrochloride (1.03 g, 4.01 mmol) in EtOH (10 ml).
After 20 min the mixture was refluxed for 5 h. After cooling,
the precipitate was suction filtered and stirred at room tempera-
ture with a mixture of 50% aqueous tetrafluoroboric acid
(10 ml) and EtOH (10 ml) for 1 h. The precipitate was suction
filtered and washed with EtOH and ether. Yield, 1.01 g (87%),
50% Ethereal tetrafluoroboric acid (10 ml) was added drop-
wise to a solution of 10c (0.10 g, 0.20 mmol) in chloroform
(20 ml). The mixture was stirred for 20 h in an open vessel at
room temperature and then ether (200 ml) was added. The
precipitate was suction filtered and washed with ether. Yield,
0.09 g (76%), dark red powder with a greenish lustre; mp
240 °C (decomp.). IR (KBr): n˜/cm−1=2923, 2853, 1614, 1596,
1559, 1516, 1465, 1318, 1299, 1253, 1193, 1179, 1084, 833, 725,
533; UV–VIS (DMSO): l /nm (log e)=325 (4.228), 469
(4.509). Calc. for (C H B F N O) [(681.4) ]: C, 61.70; H,
6.36; N, 4.11%. Found: C, 61.66; H, 6.69; N, 4.60%.
red powder; mp >250 °C (decomp.). IR (KBr): n/cm−1=1624,
˜
1604, 1576, 1492, 1336, 1192, 1084, 820; UV–VIS (DMSO):
max
35 43 2 8
2
n
n
l
[(326.1) ]: C, 55.25; H, 4.64; N, 8.59%. Found: C, 50.84; H,
/nm (log e)=461, (4.571). Calc. for (C H BF N ΩH O)
max
15 13
4
2
2
n
n
Doping of 7c with iodine26 [7c(ox); general procedure for 7, 9,
11, 12]
4.22; N 8.32%.
Poly[3-iminioprop-2-enimiumyl(p-phenylenevinylphenylene-
iminium) tetrafluoroborate] 9c
Compound 7c (0.51 g, 1 mmol) was stirred with a saturated
solution of iodine in tetrachloromethane for 30 min in the
dark. The solvent was removed in vacuo at 25 °C. Yield, 0.52 g,
black powder; ESR (solid state, MnO): g=2.0034.
1,1,3,3-Tetramethoxypropane (0.66 g, 4.02 mmol) and 50%
aqueous tetrafluoroboric acid (1 ml) were added under stirring
to a supension of 4,4∞-diaminostilbene (0.84 g, 3.99 mmol) in
EtOH (10 ml). After 20 min the mixture was refluxed for 9 h.
After cooling the precipitate was suction filtered and washed
with EtOH and ether. Yield, 1.25 g (89%), dark red powder;
mp 288–289 °C. IR (KBr): n˜/cm−1=1623, 1600, 1576, 1506,
Doping of 7c with FeCl 26 (general procedure for 7, 9, 11, 12)
3
Compound 7c (0.51 g, 1 mmol) was stirred with a 10% solution
of ferric chloride in nitromethane at room temperature for
30 min. The precipitate was suction filtered and the residue
was dried in vacuo at 25 °C. Yield, 0.49 g, black powder; ESR
(solid state, MnO): g=2.014 (br, Fe3+), 4.120 (Fe+).
1330, 1194, 1084, 1021, 830; UV–VIS (DMSO): l /nm (log
max
4
e)=492 (4.760), 509 (sh, 4.750). Calc. for (C H BF N ΩH O)
[(352.1) ]: C, 57.99; H, 4.87; N, 7.96%. Found: C, 58.25; H,
4.95; N 8.36%.
17 15
2
2
n
n
References
Poly[p-phenylene-5-aminopenta-2,4-dieniminium bromide]
11a)
1
Conjugated Polymers and Related Materials, ed. W. R. Salaneck,
I. Lundstrom and B. Ranby, Oxford University Press, Oxford,
¨
1993.
AcOH (10 drops) was added to a suspension of 1024 (0.36 g,
1.01 mmol) and p-phenylenediamine (0.11 g, 1.02 mmol) in
EtOH (10 ml) and the mixture was refluxed for 30 h. After
cooling, the precipitate was suction filtered and washed with
EtOH and ether. Yield, 0.16 g (64%), black powder; mp
183–185 °C. IR (KBr): n˜/cm−1=1616, 1549, 1501, 1311, 1150,
2
(a) H. Shirakawa, E. J. Louis, A. G. MacDiarmid, C. K. Chiang
and A. J. Heeger, J. Chem. Soc., Chem. Commun., 1977, 578; (b)
C. K. Chiang, Y. W. Park, A. J. Heeger, H. Shirakawa, E. J. Louis
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833; UV–VIS (DMSO): l /nm (log e)=595 (4.388). Calc. for
max
(C H BrN ) [(251.1) ]: C, 52.61; H, 4.42; N, 11.16%. Found:
C, 53.15; H, 5.04; N, 11.34%.
11 11
2 n
n
3
Poly[p-phenylenevinylphenylene-5-aminopenta-2,4-dieniminium
bromide] 11b
4
5
D. M. Ivory, G. G. Miller, J. M. Sowa, L. W. Shacklette,
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¨
Adv. Mater., 1998, 10, 93.
As described for 11a with 1024 (0.36 g, 1.01 mmol) and 4,4∞-
diaminostilbene (0.21 g, 1.00 mmol). Yield, 0.32 g (88%), black
powder with a greenish lustre; mp 263–264 °C. IR (KBr):
n/cm−1=1618, 1541, 1505, 1312, 1161, 836; UV–VIS (DMSO):
˜
l
6
(a) G. Wegner, Angew. Chem., 1981, 93, 352; Angew. Chem., Int. Ed.
Engl., 1981, 20, 361; (b) K. Menke and S. Roth, Chem. Unserer Zeit,
/nm (log e)=350 (4.060), 541 (4.247). Calc. for
max
J. Mater. Chem., 1998, 8(9), 2011–2018
2017

1986, 20, 1; (c) K. Menke and S. Roth, Chem. Unserer Zeit, 1986,
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20 S. Brownstein, E. J. Gabe and L. Prasad, Can. J. Chem., 1983,
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7
8
9
21 Crystal data for 6e: C
H
N O, M=328.40, monoclinic, space
22 20
2
˚
˚
group P2 /c (# 14), a=9.699(3) A, b=35.875(7) A, c=
(a) S. Dahne, Z. Chem., 1965, 5, 441; (b) S. Dahne and D. Leupold,
¨
Angew. Chem., 1966, 78, 1029; Angew. Chem., Int. Ed. Engl., 1966,
¨
1
˚
10.475(4) A, a=90.00(2)°, b=92.82(2)°, c=90.00(2)°, Z=8, D =
c
1.198 g cm−3, m=0.074 mm−1, F(000)= 1392. Data collection:
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¨
rated organic compounds, Abh. Akad. W iss. DDR Nr. 8, Akademie
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¨
M. Klessinger, Chem. Unserer Zeit, 1978, 12, 1.
¨
S. Dahne and S. Kulpe, J. Prakt. Chem., 1978, 320, 395; ( f )
max
min
33×47×53 mm, maximum measuring time 60 s, graphite mono-
˚
chromated Mo-Ka radiation (l=0.71069 A). 5376 measured, 5063
independent reflections, 3871 classed as observed (I>2sI); refined
parameters: 454/0. Solution of structure: SHELXS86, refinement
with SHELXS93. Final R =0.0632 and wR =0.1814 for 2sI; R =
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61, 85.
1
2
1
0.0806 and wR =0.1922 for all data; largest/smallest residual elec-
2
11 T. J. J. Muller, Ph. D. Thesis, Universitat Munchen, 1992.
˚
¨
¨
¨
tron density r=0.410/−0.188 e A−3. The full list of atomic coordi-
nates, bond lengths and angles have been deposited at the
Cambridge Crystallographic Data Centre (CCDC). See
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request to the CCDC for this material should quote the full litera-
ture citation and the reference number 1145/106.
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¨
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¨
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¨
25 (a) S. Hunig and W. Daum, Chem. Ber., 1955, 88, 1238; (b) S. Hunig
¨
13 L. Claisen, Ber. Dtsch. Chem. Ges., 1903, 36, 3664.
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¨
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¨
16 R. Knorr and A. Weiß, Chem. Ber., 1982, 115, 139.
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31 F. Adams, Ph. D. Thesis, Universitat Munchen, 1989.
¨
¨
18 J. Fabian and H. Hartmann, L ight Absorption of Organic
Colorants, Springer-Verlag, Berlin, 1980, ch. 12.
Paper 8/01654B; Received 27th February, 1998
2018
J. Mater. Chem., 1998, 8(9), 2011–2018