PAPER
Dialkylfluorene–Oligothiophene and Dialkylfluorene–Dithienylvinylene Alternating Copolymers
1141
mmol) in anhyd Et2O (30 mL) and stirred at r.t. for 48 h. The solu-
tion was poured into H2O containing some drops of aq HCl (3 M),
and then extracted with Et2O. The organic layer was washed with
brine and dried (Na2SO4). After evaporation of the solvent the re-
maining residue was recrystallized from EtOH.
Stille-Type Coupling Reaction; General Procedure
A solution of the bis(trimethylstannyl) compound (2 mmol), 2,7-di-
bromo-9,9-dialkylfluorene (2; 2 mmol) and Pd(PPh3)4 (80 mg, 0.07
mmol) was refluxed in degassed, anhyd toluene (50 mL) for 4–6
days under argon. After cooling to r.t., CHCl3 (50 mL) and aq HCl
(2 M; 50 mL) were added to the mixture. The organic layer was iso-
lated, washed with HCl (2 M) and aq NaHCO3. The organic phase
was dried (Na2SO4) and concentrated. The polymer was precipitat-
ed into a mixture of MeOH–acetone–aq HCl (2 M) (10:2:1 v/v/v).
The solid material was extracted for 5–7 days in a Soxhlet apparatus
with acetone to remove short chain oligomers. The resulting poly-
mers were collected and dried under vacuum. Yield: 60–85%.
Yield: 3.92 g (68%); light brown solid.
1H NMR (300 MHz, CD2Cl2): = 7.15 (d, 2 H, J = 5.1 Hz), 6.99 (d,
2 H, J = 3.9 Hz), 6.97 (s, 2 H), 6.96 (dd, 2 H).
13C NMR (75 MHz, CD2Cl2): = 142.4, 128.2, 126.5, 124.9, 121.7.
Anal. Calcd for C10H8S2 (192.30): C, 62.46; H, 4.19; S, 33.35.
Found: C, 62.50; H, 3.81; S, 31.93.
Poly{2,7-[9,9-bis(3,7,11-trimethyldodecyl)fluorene]-alt-2,5-
thienylene} (8a)
Yield: 0.98 g (73%).
Distannylated Oligothiophenes and Dithienylvinylene; General
Procedure
To a stirred cooled solution (–50 °C) of the oligothiophene, or
dithienylvinylene (12 mmol) and N,N,N ,N -tetramethylethylenedi-
amine (3.98 mL, 26.8 mmol) in anhyd hexane–THF (10:20 mL) was
added BuLi (1.6 M in hexane) (17.56 mL, 28.1 mmol) dropwise via
a syringe. The mixture was heated to reflux for 45 min and then
cooled to –78 °C. Trimethyltinchloride (28.1 mL, 28.1 mmol) was
added dropwise via a syringe, and the mixture was stirred for 2 h at
r.t.. The solution was then poured into aq NH4Cl (2 M). The aqueous
layer was extracted with Et2O. The combined organic layers were
washed with H2O, dried (Na2SO4), and the solvent was removed.
The resulting residue was recrystallized from EtOH.
1H NMR (300 MHz, C2D2Cl4): = 7.67 (2 H), 7.55 (4 H), 7.34 (2
H), 1.98 (4 H), 1.39 (6 H), 1.02 (28 H), 0.76 (24 H).
13C NMR (75 MHz, C2D2Cl4): = 151.9, 144.4, 140.6, 133.3,
129.3, 125.9, 124.9/124.2, 120.5/119.9, 55.4, 39.6, 37.6, 37.0, 33.1,
32.9, 30.9, 28.2, 25.1, 24.7, 23.0, 22.9, 20.0, 19.8. Mn = 9000.
Mw = 14 000. Mw/Mn = 1.5.
Anal. Calcd for (C47H70S)n [(667.15)n]: C, 84.62; H, 10.58; S, 4.81.
Found: C, 83.65; H, 11.03; S, 4.83.
Poly{2,7-[9,9-bis(3,7,11-trimethyldodecyl)fluorene]-alt-5,5 -
(2,2 -bithiophene)} (9a)
Yield: 1.10 g (73%).
1H NMR (300 MHz, C2D2Cl4): = 7.68 (2 H), 7.54 (4 H), 7.27 (2
H), 7.16 (2 H), 1.95 (4 H), 1.39 (6 H), 1.01 (28 H), 0.75 (24 H).
2,5-Bis(trimethylstannyl)thiophene (5)
Yield: 3.48 g (70.5%); white solid.
1H NMR (300 MHz, CD2Cl2): = 7.37 (s, 2 H), 0.37 (s, 18 H).
13C NMR (75 MHz, CD2Cl2): = 143.4, 136.2, –7.68.
Mn = 11 100. Mw = 20 800. Mw/Mn = 1.8.
Anal. Calcd for C10H20SSn2 (409.71): C, 29.32; H, 4.92; S, 7.83; Sn,
57.93. Found: C, 29.30; H, 5.27; S, 7.59.
Anal. Calcd for (C51H72S2)n [(749.27)n]: C, 81.76; H, 9.69; S, 8.55.
Found: C, 80.40; H, 9.27; S, 7.77.
5,5 -Bis(trimethylstannyl)-2,2 -bithiophene (6)
Yield: 4.25 g (72%); bright-brown solid.
1H NMR (300 MHz, CD2Cl2): = 7.20 (d, 2 H, J = 3 Hz), 7.02 (d,
2 H, J = 3.3 Hz), 0.31 (s, 18 H).
13C NMR (75 MHz, CD2Cl2): = 143.1, 137.6, 136.3, 125.1, –7.73.
Poly{2,7-[9,9-bis(2-ethylhexyl)fluorene]-alt-5,5 -(2,2 -bithio-
phene)} (9b)
Yield: 0.92 g (83%).
1H NMR (300 MHz, C2D2Cl4): = 7.68 (2 H), 7.55 (4 H), 7.24 (2
H), 7.14 (2 H), 2.00 (4 H), 0.82 (12 H), 0.59–0.49 (18 H).
Anal. Calcd for C14H22S2Sn2 (491.84): C, 34.19; H, 4.51; S, 13.04;
Sn, 48.27. Found: C, 34.26; H, 4.14; S, 12.70.
Mn = 12 300. Mw = 19 500. Mw/Mn = 1.6.
Anal. Calcd for (C37H44S2)n [(552.89)n]: C, 80.38; H, 8.02; S, 11.60.
Found: C, 79.50; H, 7.61; S, 10.90.
5,5 -Bis(trimethylstannyl)-2,2 :5 ,2 -terthiophene (7)
Yield: 5.1 g (74%); brown solid.
1H NMR (300 MHz, CD2Cl2): = 7.21 (d, 2 H, J = 3.3 Hz), 7.04 (d,
2 H, J = 3.3 Hz), 7.00 (s, 2 H), 0.33 (s, 18 H).
13C NMR (75 MHz, CD2Cl2): = 142.5, 138.0, 136.1, 134.9, 125.0,
124.3, –7.9.
Poly[2,7-(9,9-dioctylfluorene)-alt-5,5´-(2,2 -bithiophene)] (9c)
Yield: 0.80 g (72%).
1H NMR (300 MHz, C2D2Cl4): = 7.65 (2 H), 7.56 (4 H), 7.29 (2
H), 7.18 (2 H), 2.03 (4 H), 1.10 (24 H), 0.79 (6 H).
13C NMR (75 MHz, C2D2Cl4): = 152.3, 144.4, 140.7, 136.9,
133.3, 129.2, 126.0, 125.0, 124.0, 120.4, 55.7, 40.4, 32.0, 30.2,
29.4, 24.2, 22.8, 14.2.
Anal. Calcd for C18H24S3Sn2 (573.96): C, 37.67; H, 4.21; S, 16.76;
Sn, 41.35. Found: C, 37.55; H, 3.66; S, 16.74.
Mn = 12 000. Mw = 19 300. Mw/Mn = 1.6.
Bis[(5-trimethyl)stannylthien-2-yl]vinylene (4)
Yield: 4.48 g (72%); brown solid.
1H NMR (300 MHz, CD2Cl2): = 7.06 (d, 2 H, J = 3.9 Hz), 7.02 (d,
2 H, J = 3.9 Hz), 7.00 (s, 2 H), 0.31 (s, 18 H).
13C NMR (75 MHz, CD2Cl2): = 148.2, 138.2, 136.2, 127.5, 121.5,
–7.7.
Anal. Calcd for (C37H44S2)n [(552.89)n]: C, 80.38; H, 8.02; S, 11.60
Found: C, 79.71; H, 7.31; S, 11.45.
Poly{2,7-[9,9-bis(3,7,11-trimethyldodecyl)fluorene]-alt-5,5 -
(2,2 :5 ,2 -terthiophene)} (10a)
Yield: 1.37 g (82%).
1H NMR (300 MHz, C2D2Cl4): = 7.66 (2 H), 7.55 (4 H), 7.20–7.12
(6 H), 1.57 (4 H), 1.38 (6 H), 1.00–0.60 (52 H).
Anal. Calcd for C16H24S2Sn2 (517.88): C, 37.11; H, 4.67; S, 12.38;
Sn, 45.83. Found: C, 37.66; H, 4.49; S, 12.47.
Mn = 13 000. Mw = 24 400. Mw/Mn = 1.9.
Synthesis 2002, No. 9, 1136–1142 ISSN 0039-7881 © Thieme Stuttgart · New York