the monobrominated alcohol 5 (4.32 g, 97%) as a colourless
Regioregular 951 poly{3-hexylthiophene-co-3-[11-(2-tetra-
hydropyranyloxy)undecyl]thiophene} 9b. Following the pro-
liquid. R 0.30 (hexane–EtOAc, 251) (Found: C, 54.1; H, 7.6;
F
S, 9.7; Br, 23.9. C H SOBr requires C, 54.05; H, 7.6; S, 9.6;
cedure of McCullough,14,19
hexylthiophene (1.47 g, 5.95 mmol) and 2-bromo-3-
[11-(2-tetrahydropyranyloxy)undecyl]thiophene (0.28 g,
a
mixture of 2-bromo-3-
15 25
Br, 24.0%); n
(CCl )/cm−1 3635 m, 3350–3500 m,br (OH),
8
max
4
2915s, 2860s (alkane CH), 1465 m, 1410 m and 1050s (C–O);
6
d
(200 MHz, CDCl ) 1.17–1.62 (19H, m, 2∞ to 10∞-H, OH),
0.67 mmol) was copolymerised with a single addition of
H
3
2.56 (2H, t, J 7.6, 1∞-H), 3.59–3.69 (2H, m, 11∞-H), 6.79 (1H,
NiCl (dppp) and a reaction time of 66 h to give the copolymer
2
d, J 5.7, 4-H) and 7.18 (1H, d, J 5.6, 5-H); d (200 MHz,
9b (108 mg, 9%) as a deep purple solid film (insoluble in
H
C D ) 1.20–1.60 (18H, m, 2∞ to 10∞-H), 2.51 (2H, t, J 7.5, 1∞-
hexane and soluble in chloroform). l
(CHCl )/nm 450; d
6
6
max
3
H
H), 3.40 (2H, t, J 6.0, 11∞-H), 6.51 (1H, d, J 5.7, 4-H) and
6.69 (1H, d, J 5.6, 5-H); d (50 MHz, CDCl ) 25.7 (9∞-C),
29.2–29.5 (1∞ to 8∞-C), 32.8 (10∞-C), 63.1 (11∞-C), 108.8 (2-
C), 125.1 (5-C), 128.2 (4-C) and 141.9 (3-C); m/z (CI)
(MNH + 350.1153; C H N79BrOS requires 350.1153); 352,
(200 MHz, CDCl ) 0.91 (t, J 6.4, 6∞-H [3H] of hexyl ),
3
1.20–1.80 (br m, side chain CH ), 2.81 (2H, br t, J 7.6, 1∞-
C
3
2
H), 3.31–3.54 (0.2H, m, 11∞, 6∞-H [2H] of THPO-undecyl),
3.66–3.90 (0.2H, m, 11∞, 6∞-H [2H] of THPO-undecyl), 4.57
(0.1H, m, 2◊-H [1H] of THPO-undecyl) and 6.98 (1H, s, 4-
H); GPC (CHCl , 450 nm)/Da M 9500, M 13 400, polydis-
4
15 29
350 (100, 98, MNH ) and 253 (26, M−Br).
4
3
n
w
persity 1.42.
2-Bromo-3-[11-(2-tetrahydropyranyloxy)undecyl]thiophene 6
Regioregular 951 poly[3-hexylthiophene-co-3-(11-hydroxyun-
decyl)thiophene] 10b. A solution of the copolymer 9b (107 mg,
~0.58 mmol, 0.06 mmol of OTHP) in chloroform (2.5 cm3)
was added to methanol (12 cm3) to give a deep purple suspen-
sion. Dilute aqueous HCl (2 mol dm−3, 1.5 cm3) was added
and the suspension was stirred at reflux for 16 h and allowed
to cool. The precipitate was collected by centrifuge and washed
twice with methanol, washed into a flask with chloroform and
evaporated to dryness under reduced pressure to give the 951
11-hydroxyundecyl5hexyl copolymer 10b (95 mg, 93%) as a
To a solution of 2-bromo-3-(11-hydroxyundecyl)thiophene 5
(4.28 g, 12.8 mmol) in dry dichloromethane (35 cm3) was
added toluene-p-sulfonic acid (82 mg, 0.48 mmol) and 3,4-
dihydro-2H-pyran (1.5 g, 18 mmol). The solution rapidly
turned violet and, more slowly, olive. The solution was stirred
for 20 h at room temperature and washed with water and
brine, dried and the solvent removed under reduced pressure
to give a brown liquid. Flash chromatography with dichloro-
methane–hexane (151) eluent gave the protected alcohol 6
(4.78 g, 89%) as a colourless liquid. R 0.40 (CH Cl ) (Found:
F
2 2
C, 57.6; H, 7.8; S, 7.5; Br, 19.0. C H SO Br requires C, 57.5;
deep purple solid. l
max
(CHCl )/nm 450; d (200 MHz, CDCl ) 0.91 (br t, J ~6.4,
(solid)/nm 526, 550sh and 600sh,
20 33
2
H, 8.0; S, 7.7; Br, 19.1%); n
(liquid film, NaCl)/cm−1 2935s,
max
3
H
3
2855s (alkane CH), 1465 m, 1410w, 1350 m and 1035s (C–O);
6∞-H [3H] of hexyl), 1.20–1.80 (br m, side chain CH ), 2.81
2
d
(200 MHz, CDCl ) 1.20–1.45 (14H, br s, 3∞ to 9∞-H),
(2H, br t, J ~7.5, 1∞-H), 3.62 (0.2H, t, J 6.5, 11∞-H [2H] of
H
3
1.45–1.89 (10H, m, 2∞, 10∞ and 3◊ to 5◊-H), 2.55 (2H, t, J 7.6,
1∞-H), 3.38 (1H, dt, J 9.6 and 6.6, 11∞-H), 3.44–3.55 (1H, m,
6◊-H), 3.73 (1H, dt, J 9.6 and 6.8, 11∞-H), 3.82–3.93 (1H, m,
6◊-H), 4.57 (1H, m, 2◊-H), 6.79 (1H, d, J 5.7, 4-H) and 7.18
(1H, d, J 5.5, 5-H); d (200 MHz, C D ) 1.20–1.93 (24H, m,
2∞ to 10∞ and 3◊ to 5◊-H), 2.51 (2H, t, J 7.5, 1∞-H), 3.37–3.53
(2H, m, 11∞ and 6◊-H), 3.83–4.00 (2H, m, 11∞ and 6◊-H), 4.67
(1H, dd, J 3.4 and 3.4, 2◊-H), 6.51 (1H, d, J 5.6, 4-H) and
6.69 (1H, d, J 5.6, 5-H); d (50 MHz, CDCl ) 19.7 (4◊-C),
11-hydroxyundecyl) and 6.98 (1H, s, 4-H); GPC (CHCl ,
3
450 nm)/Da M 11 500, M 19 000, polydispersity 1.65.
n
w
Regioregular 951 poly[3-hexylthiophene-co-3-(11-azidounde-
cyl)thiophene] 11b. To a solution of regioregular 951 poly[3-
H
6 6
hexylthiophene-co-3-(11-hydroxyundecyl)thiophene]
10b
(77 mg, ~0.043 mmol OH) in dry THF (2 cm3) was added
triphenylphosphine (46 mg, 0.175 mmol), di-tert-butyl azo-
dicarboxylate (43 mg, 0.187 mmol) and diphenylphosphoryl
azide (39 ml, 0.181 mmol).42,48 The red solution was stirred
at room temperature and in the dark for 5 days and the THF
was then evaporated (with a stream of nitrogen). The resultant
purple solid was dissolved in chloroform (1.5 cm3) and added
to methanol (10 cm3). The purple suspension which formed
was stirred for 0.5 h and the solid was isolated by centrifuge,
washed with methanol, acetone and methanol, transferred to
a flask with chloroform and evaporated to dryness to give the
azidated copolymer 11b (63 mg, 81%) as a deep purple solid
C
3
25.5, 26.2, 29.2–29.7 and 30.8 (1∞ to 10∞, 3◊ and 5◊-C), 62.3
and 67.7 (11∞ and 6◊-C), 98.8 (2◊-C), 108.8 (2-C), 125.1 (5-
C), 128.2 (4-C) and 142.0 (3-C); m/z (CI) (MNH + 434.1728;
4
C H N79BrO S requires 434.1729) 436, 434 (3, 3, MNH ),
20 37
2
4
352, 350 (4, 4, MNH − THP group), 337 (2, M−Br), 102
4
(100, C H O ) and 85 (60, C H O).
5
10 2
5 9
3-Hexylthiophene 7
3-Hexylthiophene 7 was synthesised according to the published
procedure.41
film. n
(KBr disc)/cm−1 includes 2095w (azide); l
max
max
d
(solid/nm) 522, 550sh and 600sh, (CHCl /nm) 450;
(200 MHz, CDCl ) 0.91 (br t, J ~6.7, 6∞-H [3H] of hexyl),
1.20–1.80 (br m, side chain CH ), 2.81 (2H, br t, J ~7.4, 1∞-
H), 3.23 (0.16H, t, J ~7, 11∞-H [2H] of 11-azidoundecyl) and
3
H
2-Bromo-3-hexylthiophene 8
3
Following Bauerle,40 3-hexylthiophene 7 (16.1 g, 96 mmol)
¨
2
was mono-brominated with N-bromosuccinimide (17.5 g,
98 mmol) in dry dimethylformamide (100 cm3) at 0 °C.
Distillation of the crude product (80 °C, 0.2 mmHg) gave 2-
bromo-3-hexylthiophene 8 (18.5 g, 78%) as a colourless liquid.
6.98 (1H, s, 4-H); GPC (CHCl , 450 nm)/Da M 12 900, M
3
n
w
23 300, polydispersity 1.80; DSC: exotherm at 185 °C, max. at
200 °C (not seen on second sweep—nitrene formation and
reaction).
R
0.50 (hexane); d (200 MHz, CDCl ) 0.88 (3H, t, J 6.5,
F
H
3
6∞-H), 1.25–1.37 (6H, m, 3∞ to 5∞-H), 1.49–1.64 (2H, m, 2∞-
H), 2.56 (2H, t, J 7.6, 1∞-H), 6.79 (1H, d, J 5.6, 4-H) and
7.18 (1H, d, J 5.7, 5-H); d (200 MHz, C D ) 0.89 (3H, t, J
6.4, 6∞-H), 1.16–1.35 (6H, m, 3∞ to 5∞-H), 1.47 (2H, br quintet,
J ~7, 2∞-H), 2.48 (2H, t, J 7.6, 1∞-H), 6.49 (1H, d, J 5.6, 4-
H) and 6.68 (1H, d, J 5.7, 5-H). These data are in accord
with those previously reported.14
Summary of GPC data for all other copolymers
H
6 6
9a M 10 400, M 15 500; 10a M 11 800, M 19 600; 11a M
n
w
n
w
n
11 400, M 21 200; 9c M 11 300, M 15 800; 10c M 14 000,
w
n
w
n
M
32 700; 11c M 16 900, M 60 600; 9d M 12 800, M
w
n
w
n
w
21 200; 10d M 9800, M 24 700; 11d M 14200, M 143 700.
n
w
n
w
Regioregular poly(3-hexylthiophene) 12
Copolymerisations and copolymer reactions
The syntheses of copolymers 9a–d, 10a–d and 11a–d are
illustrated using the 951 copolymer series, 9b, 10b and 11b.
This polymer was prepared from 2-bromo-3-hexylthiophene 8
following the procedure of McCullough.14
2114
J. Mater. Chem., 1999, 9, 2109–2115