Macromolecules
ARTICLE
result, the device provided higher power conversion efficiency
compared with the device based on P3HT homopolymer.
In this paper, a novel series of charge transporting polymers
containing TPA moiety were designed and synthesized by CꢀN
coupling polymerization explained above. To the PTPA back-
bone, 2,1,3-benzothiadiazole (BTH) and 3,4-ethylenedioxythio-
phene (EDOT) were introduced for modifying optical and
electrical properties. Diblock copolymers consisting of TPA-
polymers and PEO were also prepared by terminal modification
during polymerization using PEO derivatives. The optical and
electrical properties were thoroughly examined for these TPA-
polymers. So far, although numerous works on charge transport-
ing property have been done on not only arylamine polymers but
also molecular-doped polymer blend systems,23,24 the charge
drift mobility in the block copolymer films and its dependence on
the morphology have not been profoundly concerned. We
demonstrated in this work that the hole drift mobility was
compared among TPA-containing homopolymer, random co-
polymer, and block copolymer in order to investigate structural
and morphological effects on hole-transporting ability of the
TPA-polymers.
2H), 7.72 (s, 2H), 7.65 (d, J = 8.4 Hz, 2H), 7.18ꢀ7.08 (m, 6H), 5.82
(s, 1H), 2.59 (t, J = 7.5 Hz, 2H), 1.60 (quint, J = 7.5 Hz, 2H), 1.37 (sex, J =
7.5 Hz, 2H), 0.94 (t, J = 7.5 Hz, 3H). 13C NMR (CDCl3): δ154.09, 153.88,
144.51, 139.56, 136.87, 136.39, 133.54, 131.72, 130.86, 130.68, 130.26,
129.29, 128.61, 128.19, 126.62, 122.41, 119.61, 116.08, 34.98, 33.79, 22.35,
13.99. Anal. Calcd for C28H24BrN3S: C, 65.37; H, 4.70; N, 8.17. Found: C,
65.08; H, 4.62; N, 8.17.
Synthesis of2,5-Diphenyl-3,4-ethylenedioxythiophene(6).
To a two-necked flask equipped with a stopcock and a condenser were
added 5 (12.7 g, 42.4 mmol), phenylboronic acid (11.4 g, 93.2 mmol),
Pd(PPh3)4 (0.392 g, 0.339 mmol), and distilled THF (50 mL) under
nitrogen. After 2 M K2CO3(aq) (50 mL, purged by nitrogen for 1 h) was
added, the mixture was vigorously stirred at reflux for 24 h. Chloroform
was added after cooling down to room temperature, and the mixture was
washed with water. The organic layer was dried with MgSO4 and
concentrated by a rotary evaporator. The crude product was recrystallized
from methanol to give a yellow needle crystal. The yield was 7.91 g (63%).
1H NMR (CDCl3): δ 7.79 (d, J = 7.2 Hz, 4H), 7.41 (t, J = 7.2 Hz, 4H),
7.26 (t, J = 7.2 Hz, 2H), 4.36 (s, 4H). 13C NMR (CDCl3): δ 138.56,
132.92, 128.61, 126.58, 126.07, 115.36, 64.56. Anal. Calcd for C18H14O2S: C,
73.44; H, 4.79. Found: C, 73.62; H, 4.93.
Synthesis of 2,5-Bis(40-bromophenyl)-3,4-ethylenedioxy-
thiophene (7). To a mixture of 6 (9.50 g, 32.3 mmol) and chloroform
(200 mL) were added bromine (3.31 mL, 64.6 mmol) and chloroform
(100 mL) dropwise at 0 °C, and the resulting mixture was stirred for 30
min. Additional stirring were carried out for 6 h at room temperature.
The mixture was successively washed with 3% NaOH(aq), saturated
NaHSO3(aq), and water. The organic layer was dried with MgSO4 and
concentrated by a rotary evaporator. The crude product was recrystal-
lized from hexane to give a white needle crystal. The yield was 14.1 g
(97%). 1H NMR (CDCl3): δ 7.61 (d, J = 8.4 Hz, 4H), 7.48 (d, J = 8.4 Hz,
4H), 4.37 (s, 4H). 13C NMR (CDCl3): δ 139.19, 132.00, 131.92, 127.75,
120.59, 114.86, 64.79. Anal. Calcd for C18H12Br2O2S: C, 47.81; H, 2.68.
Found: C, 47.87; H, 2.58.
’ EXPERIMENTAL SECTION
Materials. Toluene was distilled over CaH2 and stored under
nitrogen. Tetrahydrofuran (THF) was used as distilled over sodium
and benzophenone. 4,7-Dibromo-2,1,3-benzothiadiazole (1),25 4,7-bis-
(40-bromophenyl)-2,1,3-benzothiadiazole (3),26 and 2,5-dibromo-3,4-
ethylenedioxythiophene (5)27 were prepared by reported procedures.
For the preparations of 4,7-diphenyl-2,1,3-benzothiadiazole (2) and 2,5-
diphenyl-3,4-ethylenedioxythiophene (6), the modified procedure re-
ported by Fang et al. was applied.28 A monomer for poly(4-butyl-
triphenylamine), 4-(40-bromophenyl)-400-butyldiphenylamine (9), and
poly(ethylene oxide) with a 4-bromophenyl terminal (PEO-Br) were
prepared according to previous report.12 All the other reagents were used
as purchased without any further purification.
Synthesis of 2-(40-Bromophenyl)-5-[400-(4000-butylphenylamino)
phenyl]-3,4-ethylenedioxythiophene (8). To a two-necked flask
equipped with a stopcock and a condenser were added 7 (4.78 g,
10.6 mmol), 4-butylaniline (1.67 mL, 10.6 mmol), Pd(dppf)Cl2 (0.086 g,
0.106 mmol), sodium tert-butoxide (1.42 g, 14.8 mmol), and dry toluene
(75 mL) under nitrogen. The mixture was stirred at reflux for 12 h. After
cooling down to room temperature, the mixture was washed with brine.
The organic layer was dried with MgSO4 and concentrated by a
rotary evaporator. The crude product was purified by column chroma-
tography eluted with toluene/hexane (2/1 in volume ratio) to give a
Synthesis of 4,7-Diphenyl-2,1,3-benzothiadiazole (2). To a
two-necked flask equipped with a stopcock and a condenser were added 1
(10.0 g, 34.0 mmol), phenylboronic acid (9.12 g, 74.8 mmol), tetrakis-
(triphenylphosphine)palladium(0) (Pd(PPh3)4) (0.078 g, 0.068 mmol),
and distilled THF (50 mL) under nitrogen. After 2 M K2CO3(aq)
(50mL, purgedbynitrogenfor 1 h) wasadded, themixture wasvigorously
stirred at reflux for 24 h. Chloroform was added after cooling down to
room temperature, and the mixture was washed with water. The organic
layer was dried with MgSO4 and concentrated by a rotary evaporator. The
crude product was recrystallized from hexane to give a yellow needle
crystal. Yield was 7.31 g (75%). 1H NMR (CDCl3): δ 7.97 (d, J = 7.2 Hz,
4H), 7.80 (s, 2H), 7.56 (t, J = 7.2 Hz, 4H), 7.47 (t, J = 7.2 Hz, 2H). 13C
NMR (CDCl3): δ 154.11, 137.42, 133.37, 129.24, 128.62, 128.36, 128.12.
Anal. Calcd for C18H12N2S: C, 74.97; H, 4.19; N, 9.71. Found: C, 75.01;
H, 4.29; N, 9.96.
1
yellow powder. The yield was 2.34 g (43%). H NMR (acetone-d6):
δ 7.69ꢀ7.58 (m, 4H), 7.51 (d, J = 8.7 Hz, 2H), 7.27 (s, 1H), 7.14ꢀ
7.05 (m, 6H), 4.38 (s, 4H), 2.57 (t, J = 7.5 Hz, 2H), 1.59 (quint,
J = 7.5 Hz, 2H), 1.37 (sex, J = 7.5 Hz, 2H), 0.93 (t, J = 7.5 Hz, 3H). 13C
NMR (acetone-d6): δ 144.70, 141.67, 140.75, 138.77, 136.40, 133.64,
132.52, 129.98, 128.12, 127.98, 125.07, 120.06, 119.56, 117.30, 117.08,
112.29, 65.74, 65.45, 35.61, 34.67, 23.01, 14.25. Anal. Calcd for
C28H26BrNO2S: C, 64.61; H, 5.04; N, 2.69. Found: C, 64.82; H, 5.09;
N, 2.42.
00
Synthesis of 4-(40-Bromophenyl)-7-[4 -(4000-butylphenylamino)
phenyl]-2,1,3-benzothiadiazole (4). To a two-necked flask equipped
with a stopcock and a condenser were added 3 (8.00 g, 17.9 mmol),
4-butylaniline (2.83 mL, 17.9 mmol), [1,10-bis(diphenylphosphino)
ferrocene]dichloropalladium(II) (Pd(dppf)Cl2) (0.14 g, 0.18 mmol),
sodium tert-butoxide (2.41 g, 25.1 mmol), and dry toluene (50 mL) under
nitrogen. The mixture was stirred at reflux for 12 h. After cooling down to
room temperature, the mixture was washed with brine. The organic layer
was dried with MgSO4 and concentrated by a rotary evaporator. The crude
product was purified by column chromatography eluted with toluene/
hexane (4/1 in volume ratio) to give an orange crystal. The yield was 2.50 g
(27%). 1H NMR (CDCl3): δ 7.89 (d, J = 8.4 Hz, 2H), 7.84 (d, J = 8.4 Hz,
Synthesis of Poly(ethylene oxide) with a Diphenylamine
Terminal (PEO-DPA). To a two-necked flask equipped with a stop-
cock and a condenser were added PEO-Br (Mn = 2000, 4.30 g,
2.15 mmol), aniline (0.39 mL, 4.30 mmol), sodium tert-butoxide
(0.413 g, 4.30 mmol), Pd(OAc)2 (0.0097 g, 0.043 mmol), tri-tert-
butylphosphine (41.7 μL, 0.172 mmol), and dry THF (10 mL) under
nitrogen. The mixture was stirred at reflux for 24 h. After cooling to
room temperature chloroform was added, and the mixture was washed
with brine. The organic layer was dried with MgSO4 and concentrated
by a rotary evaporator. The crude product was washed with diethyl ether
1
and dried. The yield was 3.55 g (83%). H NMR (CDCl3): δ 7.20
5201
dx.doi.org/10.1021/ma200940v |Macromolecules 2011, 44, 5200–5208