LIQUID CRYSTALLINE POLYMERS BASED POLYTHIOPHENE
693
ꢁ
3
.56 (2H, q), 3.62 (2H, t), 3.90 (2H, t), 6.81 (2H, d), 7.88 (2H, Preparation of Poly{2-[N-ethyl-N-[4-[(4 -nitrophenyl)azo]-
13
d), 7.92 (4H, d), 8.32 (2H, d) ppm. CNMR (CDCl3): δ 12.1, phenyl] amino] ethyl-3- thiophene acetate-co- thiophene},
4
1
6.4, 52.8, 60.1, 112.3, 122.5, 124.7, 126.6, 143.8, 147.2, 151.6, Poly(Th3AA-RedI-co-Th)
57.2 ppm.
The typical synthesis procedures utilized can be described
as fellows: The 0.1 g (0.22 mmol) of monomer (Th3AA-RedI)
and 0.0092 g (0.1 mmol) of monomer thiophene in 10 mL of
THF was added dropwise to a suspension 0.233 g (0.65 mmol)
of Fe(ClO4)3 in 10 mL of THF under nitrogen atmosphere. The
ꢁ
Preparation of {2-[N-ethyl-N-[4-[(4 -nitrophenyl)azo]-
phenyl] amino] ethyl-3- thiophene acetate}, (Th3AA-RedI)
A total 1 g (0.012 mol) of thiophene-3-acetic acid and 1.884 g
◦
mixture was stirred at 50 C temperature for 24 h. The copolymer
(
0.006 mol) of RedI (crystallized in isopropyl alcohol) were
in solution was precipitated by addition of excess methanol. The
precipitation was extracted using boiling absolute ethanol. The
precipitate was dried under vacuum. FT-IR (KBr pellets, υ in
dissolved in 50 mL of dry THF. Then 1.279 g (0.0062 mol) of
N-N-dicyclohexyl carbodiimide (DCC) and 0.109 g (0.9 mmol)
of 4-(dimethylamino) pyridine (DMAP) were added to the vig-
orously stirred solution. The stirring was continued for 5 h. The
mixture was then filtered, and the solvent was removed by rotary
evaporator under vacuum. The product was purified by column
chromatography (silica gel, petroleum ether: ethyl acetate =
−1
cm ), υ: 2920 (υC-H, Al), 1713 (υC O), 1600 (υN N), 1516,
338 (υNO2), 1463 (υC C), 1133 (υC-O), 845 (υC-H, OOP), 650
1
−
−1
1
6
(
(
υ, ClO ) cm . H-NMR (d - DMSO): δ 1–1.22 (broad), 3.38
broad), 6.7–8.32 (broad).
4
2
:2, v/v), followed by recrystallized from petroleum ether/ethyl
acetate to yield red crystals (Compound 2 was obtained as red
crystals). Yield: 55%, UV (THF); λmax = 446 nm (0.26 inten-
sity), 253 nm (2.35 intensity), 212 nm (3.26 intensity). FT-IR
−1
(
KBr pellets, υ in cm ), υ: 3100 (υC-H, Ar), 2910 (υC-H, Al),
1
625 (υC O), 1601 (υN N), 1515, 1340 (υNO2), 1627, 1455
−1
1
6
(
υC C), 1140 (υC-O), 859 (υC-H, OOP) cm . H-NMR (d -
DMSO): δ 1.24 (3H, t), 3.47 (2H, q), 3.66 (2H, t), 3.79 (2H,
s), 4.33 (2H,t), 6.79 (2H, d), 7.01–7.30 (4H thiophene, m), 7.87
13
6
(
2H, d), 8.33 (2H, d), ppm. CNMR (d - DMSO): δ 12.2, 35.7,
4
1
5.5, 48.6, 61.8, 111.4, 122.6, 123.1, 124.6, 126, 126.2, 128.4,
43.8, 147.3, 151, 156.7, 171 ppm.
ꢁ
Preparation of Poly{2-[N-ethyl-N-[4-[(4 -nitrophenyl)azo]-
phenyl] amino] ethyl-3- thiophene acetate}, Poly(Th3AA-RedI)
Polymerization was carried out as follows: The 0.5 g
(0.1 mmol) of monomer (Th3AA-RedI) in 25 mL THF was
added dropwise to a suspension 0.1062 g, (0.3 mmol) of
Fe(ClO4)3 in 20 mL of THF under nitrogen atmosphere. The
◦
mixture was stirred at 50 C temperature for 24 h. The polymer-
ization mixture was added dropwise into 100 mL of methanol.
The precipitates were filtrated, dissolved in 5 mL of THF, and
reprecipitated into 100 mL of methanol. This procedure was
repeated three time until the unreacted monomers were com-
pletely removed. Finally, the polymer was dried under vacuum
◦
at 25 C to constant weight. (Compound 3 was obtained). UV
(
2
THF): λmax = 446 nm (0.25 intensity), 297 nm (0.54 intensity),
53 nm (2.74 intensity), 211 nm (3.94 intensity). FT-IR (KBr
−
1
pellets, υ in cm ), υ: 3100 (υC-H, Ar), 2929 (υC-H, Al), 1732
(
8
−1
υC O), 1627 (υN N), 1516, 1388 (υNO2), 1134 (υC-O) cm ,
−1
23 (υC-H, OOP), 630 (υ, ClO4 ) cm .
1
6
H-NMR (d - DMSO): δ 1.25 (3H, t), 3.61 (2H, q), 3.47
2H, q), 3.67 (2H, t), 3.79 (2H, s), 4.35 (2H, t), 6.80 (2H, d),
.01–7.30 (4H thiophene, m), 7.87–7.94 (4H, m), 8.31–8.34
(
7
13
6
(2H,d) ppm. CNMR (d - DMSO): δ 12.2, 35.7, 45.6, 48.7,
6
1
1.8, 111.4, 122.6, 123.1, 124.7, 125.9, 126, 128.4, 143.8, 147.4,
51.2, 156.7, 171 ppm.
SCH. 1. Schematic reactions for route synthesis of poly(Th3AA-RedI).