Alkyne Functionalized P3HT (P3HT-Alkyne): P3HT-Alkyne was synthesized according to a reported procedure.9 A 0.5 M LiCl solution was prepared by weighing 1.06 g LiCl into a Schlenk flask and subsequently drying for 4 h in vacuo at 140 °C.
50 mL anhydrous THF was added and the solution was stirred overnight to assure a complete dissolution of the LiCl. A dry Schlenk flask was charged with 6.15 g (18.86 mmol) 2,5-dibromo-3-hexyl-thiophene under N2 atmosphere. 37.8 mL of the 0.5 M LiCl solution in THF were added. 14.8 mL (18.10 mmol) of a 1.25 M solution of t-BuMgCl in THF were added and the reaction mixture was stirred for 24 h to ensure the complete formation of the active Grignard species. The solution was diluted with 136 mL THF and the polymerization was started by adding 98.8 mg (118.60 µmol) Ni(dppp)Cl2 suspended in 2 mL THF. The polymerization was terminated by adding 8 mL (3.77 mmol) of a 0.5 M solution of EthynylMgCl in THF/Toluene after 33 min. The solution was stirred for further 15 min and the polymer was subsequently precipitated in methanol. The polymer was dried and redissolved in CHCl3. The solution was filtered over a short aluminum oxide column to remove residual LiCl and Ni(dppp)Cl2, evaporated with the rotary evaporator to get a concentrated solution, and precipitated again in methanol. m =2.18 g, Mn,SEC = 18300 g mol-1, PDI = 1.19. 1H NMR (300 MHz, CHCl3): δ (ppm) 6.98 (s, 1H), 3.52 (s, 1H), 2.81 (t, 2H, J = 7.7 Hz), 1.80-1.60 (m, 2H), 1.50-1.25 (m, 6H), 0.98-0.83 (m, 3H); IR (ATR): ν(cm-1) 3310 (C≡C-H2), 2095 (C≡C)
P3HT-Macro RAFT-agent (P3HT-RAFT): A dry flask was charged with 1.6 g (133.0 µmol) P3HT-Alkyne and 596.4 mg (1.33 mmol) 2-Dodecylsulfanyl-thiocarbonylsulfanyl-2-methylpropionicacid-3-azido-propylester. The reagents were dissolved in 400 mL THF and the solution was degassed with N2 for 20 min. 8 mL (47.04 mmol) DIPEA and 190.6 mg (1.33 mmol) equivalents CuI were added. The mixture was stirred at 40 °C for 6 days. The solution was filtered over a short aluminum oxide column to remove the catalyst and dried in vacuo. The polymer was precipitated
Impact of Molecular Dynamics on Structure Formation of Donor-Acceptor Block Copolymers
79
from concentrated chloroform solutions in methanol (twice) and hexanes. m = 1.40 g, Mn,SEC = 18400 g mol-1, PDI = 1.18. 1H NMR (300 MHz, CHCl3): δ (ppm) 6.98 (s, 1H), 2.81 (t, 2H, J = 7.7 Hz), 1.80-1.60 (m, 2H), 1.50-1.25 (m, 6H), 0.98-0.83 (m, 3H); IR (ATR):
ν(cm-1) 1738 (C=O).
P3HT-b-poly(4-(3`-trimethylsilylpropargyloxystyrene) (P3HT-b-PTMSPOS):
A dry Schlenk flask was charged with 675 mg (56.23 µmol) P3HT-RAFT agent, 5.18 g (22.5 mmol) (3`-trimethylsilylpropargyloxy)-styrene and 3.69 mg (22.5 µmol) AIBN.
The reagents were dissolved in 23 mL 1,2,4-Trichlorobenzene and the solution was degassed with N2 for 20 min. The polymerization was started by immersing the Schlenk flask into an 80 °C warm oil bath. The conversion was controlled via NMR. After the projected conversion was achieved the polymerization was terminated by immersing the flask into liquid nitrogen. The resulting polymers were precipitated in methanol, redissolved in the smallest possible amount of chloroform and precipitated in hexane.
m =950 mg, Mn,SEC = 22200 g mol-1, PDI = 1.37, Conversion = 6.7 %. 1H NMR (300 MHz, CHCl3): δ (ppm) 6.98 (s, 1H), 6.8-6.15 (br, 4H), 4.70-4.50 (br, 2H), 2.81 (t, 2H, J = 7.7 Hz), 1.78-1.60 (m, 2H), 1.50-1.20 (m, 9H), 0.97-0.83 (m, 3H), 0.18 (s, 9H); IR(ATR): ν(cm-1) 2180 (C≡C), 1731 (C=O).
Synthesis of P3HT-b-poly(4-propargyloxystyrene) (P3HT-b-PPOS): 1.36 g P3HT-b-TMSPPOS was dissolved in 175 mL THF and the solution was degassed with N2 for 20 min. 245 mg acetic acid and 12.9 mL of a degassed 0.5 M TBAF solution in THF was added with a syringe. The solution was stirred at room temperature for 48 h. The polymer was precipitated in methanol. m= 822 mg, Mn,SEC = 21900 g mol-1, PDI = 1.42.
1H NMR (300 MHz, CHCl3): δ (ppm) 6.98 (s, 1H), 6.8-6.15 (br, 4H), 4.72-4.52 (br, 2H), 2.80 (t, 2H, J = 7.7 Hz), 2.58- 2.45 (br, 1H), 1.80-1.60 (m, 2H), 1.50-1.20 (m, 9H), 0.99-0.79 (m, 3H); IR (ATR): ν(cm-1) 2180 (C≡C), 1731 (C=O).
Impact of Molecular Dynamics on Structure Formation of Donor-Acceptor Block Copolymers
80
P3HT-b-PPBI 1: A dry Schlenk flask was charged with 200 mg P3HT-b-PPOS and 257 mg (343 µmol, 1.1 eq.) PBI-N3 1. The reagents were dissolved in 60 mL 1,2-dichlorobenzene and the solution was degassed for 20 min with N2. 15 drops of the CuBr/PMDETA stock solution were added and the mixture was stirred at rt for 72 h.
The polymer was filtered over aluminum oxide, precipitated in ethyl acetate and dried.
The polymer was purified by column chromatography (toluene, ethylacetate, CHCl3, CHCl3: methanol 98:2) and subsequently precipitated in methanol from a concentrated CHCl3 solution. m =372 mg, Mn,SEC = 69500 g mol-1, PDI = 1.25. 1H NMR (300 MHz, CHCl3): δ (ppm) 8.54-7.41 (br, 9H), 6.98 (s, 1H), 6.91-6.21 (br, 4H), 5.37-4.82 (br, 3H), 4.51-4.24 (br, 2H), 4.15-3.82 (br, 2H), 2.80 (t, 2H, J = 7.7 Hz), 2.35-1.07 (m, 47H), 0.99-0.75 (m, 9H,); IR (ATR): ν(cm-1) 3058, 2953, 2923, 2854, 2166, 1695, 1654, 1594, 1579, 1508, 1456, 1437, 1404, 1377, 1340, 1244, 1215, 1174, 1125, 1109, 1087, 1047, 1008, 962, 851, 825, 810, 795, 746, 722.
P3HT-b-PPBI 2: A dry Schlenk flask was charged with 150 mg P3HT-b-PPOS and 211 mg (257 µmol, 1.1 eq.) PBI-N3 2. The reagents were dissolved in 22.5 mL 1,3,5-trichlorobenzene and the solution was degassed for 20 min with N2. 8 drops of the CuBr/PMDETA stock solution were added and the mixture was stirred at rt for 72 h.
The polymer was filtered over aluminum oxide, precipitated in ethyl acetate and dried.
The polymer was purified by column chromatography (toluene, ethylacetate, CHCl3, CHCl3: methanol 98:2) and subsequently precipitated in methanol from a concentrated CHCl3 solution. m =254 mg, Mn,SEC = 77700 g mol-1, PDI = 1.23. 1H NMR (300 MHz, CHCl3): δ (ppm) 8.30-7.32 (br, 9H), 6.98 (s, 1H), 7.00-6.31 (br, 4H), 5.74-5.46 (br, 1H), 5.33-4.96 (br, 2H), 4.56-4.31 (br, 2H), 4.31-3.86 (br, 6H), 3.86-3.38 (m, 16H), 3.38-3.19 (br, 6H), 2.80 (t, 2H, J = 7.7 Hz), 2.16-1.06 (m, 19H), 0.99-0.77 (m, 3H); IR (ATR): ν(cm-1) 3056, 2953, 2923, 2856, 2167, 2051, 1694, 1654, 1593, 1578, 1508, 1437, 1404, 1341, 1302, 1245, 1200, 1178, 1100, 1049, 851, 825, 810, 793, 745.
Impact of Molecular Dynamics on Structure Formation of Donor-Acceptor Block Copolymers
81 Homopolymers
Synthesis of PTMSPOS: 4-(3`-trimethylsilylpropargyloxy)styrene (TMSPOS) (75 eq), N-t-butyl-O-[1-[4-(chloromethyl)-phen-yl]ethyl]-N-(2-methyl-1-phenylpropyl)-hydroxylamine (1 eq, Hawker-Initiator) and 2,2,5-trimeth-yl-4-phenyl-3-azahexane-3-nitroxide (0.1 eq, free 2,2,5-trimeth-yl-4-phenyl-3-azahexane-3-nitroxide) were dissolved in 1.6 mL o-DCB per 1 g monomer and degassed by three freeze–pump–thaw cycles. The polymerization was started by the immersion of the reaction vessel in a 125 °C warm oil bath. The reaction was quenched by cooling in liquid nitrogen and precipitated into cold methanol twice from a concentrated THF solution. PTMSPOS 1: 654 mg, Mn,SEC = 9100 g mol-1, PDI = 1.32; 1H NMR (300 MHz, CHCl3): δ (ppm) 6.9–6.18 (br, 4H), 4.63 (s, 2H), 1.79–0.92 (br, 2H), 0.23 (s, 9H). PTMSPOS 2: 1.2 g, Mn,SEC = 9300 g mol-1, PDI = 1.11; 1H NMR (300 MHz, CHCl3):
δ (ppm) 6.9–6.18 (br, 4H), 4.63 (s, 2H), 1.79–0.92 (br, 2H), 0.23 (s, 9H)
Synthesis of PPOS: PTMSPOS 1/ PTMSPOS 2 was dissolved in THF, cooled to 0 °C and degassed by purging with nitrogen. 3 eq. of a degassed 0.5 M solution of tetrabutylammonium fluoride trihydrate in THF and 3 eq. of acetic acid were added via syringe. The mixture was stirred overnight and the polymer was precipitated in methanol twice from a concentrated THF solution. PPOS 1: 330 mg, Mn,SEC = 7400 g mol-1, PDI = 1.11; 1H NMR (300 MHz, CHCl3): δ (ppm) 6.9–6.18 (br, 4H), 4.63 (s, 2H), 2.52 (br, 1H), 1.79–0.92 (br, 2H); IR (ATR): ν(cm-1) 3286 (C≡C–H), 2120 (C≡C).
PPOS 2: 500 mg, Mn,SEC = 7500 g mol-1, PDI = 1.21; 1H NMR (300 MHz, CHCl3): δ (ppm) 6.9–6.18 (br, 4H), 4.63 (s, 2H), 2.52 (br, 1H), 1.79–0.92 (br, 2H); IR (ATR): ν(cm-1) 3286 (C≡C–H), 2120 (C≡C).
Impact of Molecular Dynamics on Structure Formation of Donor-Acceptor Block Copolymers
82
PPBI 1: The synthesis of PPBI 1 was published by Lang and Thelakkat.6 The polymer was synthesized according to the general method above and extracted with methyl ethyl ketone. 50 mg, Mn,SEC = 59200 g mol-1, PDI = 1.09; 1H NMR (300 MHz, CHCl3): δ (ppm) 8.45–7.40 (br, 9H), 7.00–6.10 (br, 4H), 5.35–4.86 (br, 3H), 4.50–4.24 (br, 2H), 4.18–3.80 (br, 2H), 2.40–1.00 (m, 39H), 0.83 (br, 6H).
PPBI 2: A dry Schlenk flask was charged with 49.8 mg PPOS 2 and 287.7 mg (362 µmol, 1.5 eq.) PBI-N3 2. The reagents were dissolved in 20 mL 1,2-tdichlorobenzene and the solution was degassed for 20 min with N2. 10 drops of the CuBr/PMDETA stock solution were added and the mixture was stirred at 40 °C for 5 days. The polymer was filtered over aluminum oxide, precipitated in methanol. The polymer was purified via extraction with a soxleth apparatus with methyl ethyl ketone. 254 mg, Mn,SEC = 43500 g mol-1, PDI = 1.14; 1H NMR (300 MHz, CHCl3): δ (ppm) 8.30–7.32 (br, 9H), 7.05–6.20 (br s, 4H), 5.72–5.40 (br, 1H), 5.30–4.95 (br, 2H), 4.54–4.25 (br, 2H), 4.25–4.10 (br, 2H), 4.10–3.85 (br, 4H), 3.85–3.40 (m, 16H), 3.30 (m, 6H) 2.39–1.40 (m, 11H).
Model Compounds
1-Isopropyl-4-propargyloxybenzene: 5.00 g (36.71 mmol) p-isopropylphenole and 50 mL acetone were added to a 250 mL Schlenk flask. 9.56g (73.42 mmol) KCO3
and 1.94 g (7.34 mmol) 18-Crown-6 were added and the mixture was refluxed. 8.19 g (55.07 mmol) of a 80 wt% solution of propargylbromide in toluene was added and the mixture was stirred at 60 °C for 20 h. 200 mL water and 80 mL chloroform were added and the organic phase was separated. The aqueous phase was extracted 3 more times with 80 mL chloroform each. The combined organic phases were washed 3 times with water and subsequently dried over Na2SO4 and the solvent wash evaporated in vacuo.
The crude product was purified by distillation in vacuo. Yield = 5.8 g (33.29 mmol, 91 %); 1H NMR (300 MHz, CHCl3): δ (ppm) 7.23-7.12 (m, 2H), 6.98–6.87 (m, 2H), 4.68 (d, J = 2.4 Hz, 2H), 2.98 (dq, J = 7.0 Hz, 1H), 2.53 (t, J = 2.4 Hz, 1H), 1.25 (d, J = 7.0 Hz, 6H).
Impact of Molecular Dynamics on Structure Formation of Donor-Acceptor Block Copolymers
83
PBI 1: A dry Schlenk flask was charged with 63.9 mg (398 µmol, 1.5 eq) 1-isopropyl-4-propargyloxybenzene and 200.0 mg (265 µmol) PBI-N3 1 and 15 mL THF. The solution was degassed for 20 min with N2 and 6 drops of the CuBr/PMDETA stock solution were added. The mixture was stirred at 40 °C for 24 h. The mixture was filtered over aluminum oxide and the product was precipitated in methanol. The product was freeze dried from benzene and dried in vacuo at 80 °C. The product was obtained as red solid. m =204 mg; 1H NMR (300 MHz, CHCl3): δ (ppm) 8.76–8.51 (m, 8H), 7.60 (s, 1H), 7.18-7.09 (m, 2H), 6.98–6.84 (m, 2H), 5.29-5.09 (s, 3H), 4.35 (t, J = 7.2 Hz, 2H), 4.19 (t, J = 7.5 Hz, 4H), 2.85 (dq, J = 7.0 Hz, 1H), 2.34-2.14 (m, 2H), 2.00-1.80 (m, 4H), 1.80-1.67 (m, 2H), 1.52-1.08 (m, 28H), 1.21 (d, J =7.0 Hz, 6H), 0.87-0.78 (m, 6H).
PBI 2: A dry Schlenk flask was charged with 95.0 mg (546 µmol, 2.9 eq) 1-isopropyl-4-propargyloxybenzene and 150.0 mg (189 µmol) PBI-N3 2 and 20 mL THF. The solution was degassed for 20 min with N2 and 6 drops of the CuBr/PMDETA stock solution were added. The mixture was stirred at 40 °C for 24 h. The mixture was filtered over aluminum oxide and the solvent was removed with the rotary evaporator.
The excess 1-isopropyl-4-propargyloxybenzene was removed in vacuo at 80°C for 12 h.
The product was obtained as dark red solid after freeze drying from benzene. m =137 mg; 1H NMR (300 MHz, CHCl3): δ (ppm) 8.63–8.36 (m, 8H), 7.63 (s, 1H), 7.23-7.12 (m, 2H), 6.98–6.87 (m, 2H), 5.78–5.63 (m, 1H), 5.18 (s, 2H), 4.43–4.33 (t, J = 7.2 Hz, 2H), 4.27-4.14 (m, 4H), 4.04-3.95 (m, 2H), 3.80-3.52 (m, 12H), 3.30-3.24 (m, 4H), 3.32-3.25 (s, 6H), 2.94-2.75 (dq, J = 7.0 Hz, 1H), 2.05-1.88 (m, 2H), 1.87-1.70 (m, 2H), 1.58-1.37 (m, 4H), 1.20 (d, J = 7.0 Hz, 6H).
Impact of Molecular Dynamics on Structure Formation of Donor-Acceptor Block Copolymers