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1 UPPRTIG IFRMATI Influence of the annealing temperature on the photovoltaic performance and film morphology applying novel thermocleavable materials Martin Helgesen a,*, Morten Bjerring b, iels Chr. ielsen b and Frederik C. Krebs a a Risø ational Laboratory for ustainable Energy, Technical University of Denmark, Frederiksborgvej 399, DK-4000 Roskilde, Denmark. b Center for Insoluble Protein tructures (inpi), Interdisciplinary anoscience Center (ia) and Department of Chemistry, University of Aarhus, DK-8000 Aarhus C, Denmark. manp@risoe.dtu.dk Table of Contents: General experimental details 1-2 ynthetic procedures and characterization data H-MR and 13 C-MR spectra 8-15 FTIR spectra of T1 and T2 16 General methods. Molecular weights were determined using size exclusion chromatography in HPLCgrade chloroform against polystyrene standards on a KAUER chromatograph with a refractive index detector and a diode array UV-vis detector. UV-vis absorption spectra were measured with a Perkin- Elmer Lambda 900 spectrometer. FTIR spectroscopy was conducted with a pectrum ne from Perkin 1

2 Elmer (4 cm -1 resolution, 32 scans summation). TGA experiments were performed with a dynamic heat rate (10 C/min) under an Argon atmosphere (50 ml/min) in the temperature range C. The samples were dried at 50 C for 24 hours in a vacuum oven prior to analysis. AFM images were taken on a anos multimode AFM (Bruker). Around 9 mg of T1 and T2 was packed into 2.5 mm rotors and was used for the solid-state MR experiments at a 9.4 T static magnetic field, corresponding to a 1 H resonance frequency of 400 MHz. Each spectrum was acquired with scans except the spectrum in Fig. 3c, which used scans, and the MA speed was 18 khz for all experiments. Unless stated otherwise all reagents and solvents were obtained from Aldrich and used without further purification. Dichloromethane, THF and toluene were dried with molecular sieves (3 Å) and used directly without filtration or distillation. B was recrystallised from water and dried at 70 C in vacuum. Evaporation was performed on a rotary evaporator at 40 C. MR spectra were obtained on Bruker 500 MHz or 250 MHz spectrometers. Melting points were determined on an electrothermal instrument and are uncorrected. 7a, 1 7b 2 and 8 3 were prepared according to literature procedures or slight modifications thereof. 2-methyl-2-hexyl thiophene-3-carboxylate (2). A mixture of thiophene-3-carboxylic acid (1) (5 g, 39 mmol), DMAP (5 g, 41 mmol) and 2-methyl-2-hexanol (6.1 ml, 43 mmol) in dry methylene chloride (50 ml) was stirred at room temperature under argon for 15 min., -diisopropylcarbodiimide (6,7 ml, 43 mmol) was added and the reaction mixture was heated to 40 C and stirred for 24 hours. After cooling to room temperature the reaction mixture was concentrated on celite in vacuum. Dry column chromatography (silica gel μm, eluted with EtAc/Heptane, gradient 0-3% EtAc) afforded 2. 1 Edder, C.; Armstrong, P.B.; Prado, K.B.; Fréchet, J.M.J. Chem.Comm. 2006, Helgesen, M.; Gevorgyan,. A.; Krebs, F. C.; Janssen, R. A. J. Chem. Mater. 2009, 21 (19), Helgesen, M.; Krebs, F. C. Macromolecules 2010, 43,

3 Yield: 7.5 g (85 %), colourless oil. 1 H MR (250 MHz, CDCl 3 ) δ = 8.00 (dd, J = 3.1 Hz, 1.2 Hz, 1H), 7.47 (dd, J = 5.1 Hz, 1.2 Hz, 1H), (m, 1H), (m, 2H), 1.55 (s, 6H), (m, 4H), (m, 3H). 13 C MR (250 MHz, CDCl 3 ) δ = , , , , , 83.17, 40.49, (2 signals), 22.70, methyl-2-hexyl 2-(trimethylstannyl)thiophene-3-carboxylate (3). 10 ml dry THF was cooled to -10 C under argon followed by addition of 10 ml n-butyllithium (1.6 M in hexane). Then a solution of 2.4 ml diisopropylamine and 7.6 ml dry THF was added slowly and the reaction mixture was stirred for 30 min. 20 ml (10 mmol) of the freshly prepared solution of lithium diisopropylamine was added slowly to a cooled solution (-78 C) of 2 (2 g, 8.8 mmol) in dry THF (20 ml). The reaction mixture was stirred for 1 hour at -78 C under argon followed by dropwise addition of trimethyltin chloride (2.6 g, 13 mmol) dissolved in 5 ml dry THF. The reaction mixture was allowed to warm to room temperature and stirred for 2 hours. Water was added to the reaction mixture followed by extraction with ether. The combined organic phase was washed with water, dried over magnesium sulfate, filtered and concentrated in vacuum. The residue was dissolved in heptane/etac (19:1) and quickly passed through a plug of aluminium oxide pretreated with triethylamine. Yield: 2.7 g (79 %), light yellow oil. 1 H MR (250 MHz, CDCl 3 ) δ = (m, 2H), (m, 2H), 1.54 (s, 6H), (m, 4H), (m, 3H), (m, 9H). 13 C MR (250 MHz, CDCl 3 ) δ = , , , , , 82.85, 40.66, 26.13, 26.08, 22.99, 13.99,

4 2-methyl-2-hexyl 5-bromothiophene-3-carboxylate (5). A mixture of 4 (4.5 g, 22 mmol), DMAP (2.8 g, 23 mmol) and 2-methyl-2-hexanol (3.4 ml, 24 mmol) in dry methylene chloride (50 ml) was stirred at room temperature under argon for 15 min., -diisopropylcarbodiimide (3.7 ml, 24 mmol) was added and the reaction mixture was heated to 40 C and stirred for 24 hours under argon. After cooling to room temperature the reaction mixture was concentrated on celite in vacuum. Dry column chromatography (silica gel μm, eluted with EtAc/Heptane, gradient 0-3% EtAc) afforded 5. Yield: 5.1 g (77 %), colourless oil. 1 H MR (250 MHz, CDCl 3 ) δ = 7.89 (d, J = 1.5 Hz, 1H), 7.40 (d, J = 1.5 Hz, 1H), (m, 2H), 1.53 (s, 6H), (m, 4H), 0.92 (t, J = 7.0 Hz, 3H). 13 C MR (250 MHz, CDCl 3 ) δ = , , , , , 83.78, 40.59, (2 signals), 22.79, bis(2-methyl-2-hexyl) 2,2'-(benzo[c][1,2,5]thiadiazole-4,7-diyl)bis(thiophene-3-carboxylate) (6a). To a solution of 4,7-dibromobenzo[c][1,2,5]thiadiazole (808 mg, 2.75 mmol) and 3 (2.46 g, 6.32 mmol) in 20 ml THF/DMF (1:1) was added bis(triphenylphosphine)palladium(ii) dichloride (193 mg, mmol).the reaction mixture was stirred at 90 C for 20 hours under argon. After cooling to room temperature water was added to the reaction mixture followed by extraction with dichloromethane. The combined organic phase was dried over magnesium sulfate, filtered and concentrated on celite in vacuum. Dry column chromatography (silica gel μm, eluted with EtAc/Heptane, gradient 0-7% EtAc) afforded 6a. Yield: 984 mg (61 %), yellow oil. 1 H MR (250 MHz, CDCl 3 ) δ = 7.70 (s, 2H), 7.59 (d, J = 5.3 Hz, 2H), 7.39 (d, J = 5.3 Hz, 2H), (m, 4H), 1.19 (s, 12H), (m, 8H),

5 (t, J = 7.0 Hz, 6H). 13 C MR (250 MHz, CDCl 3 ) δ = , , , , , , , , 83.18, 40.46, 25.87, 25.74, 22.93, bis(2-methyl-2-hexyl) 5,5'-(benzo[c][1,2,5]thiadiazole-4,7-diyl)bis(thiophene-3-carboxylate) (6b). 4,7-bis-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-benzo-[c]-[1,2,5]-thiadiazole (1.27 g, 3.27 mmol), 5 (2.20 g, 7.20 mmol), Pd 2 dba 3 (75 mg, mmol) and tri-(o-tolyl)phosphine (199 mg, 0.65 mmol) was dissolved in dry THF (20 ml) and stirred for 15 min at RT under argon. Then K 2 C 3 (2.7 g, 19.6 mmol) and degassed water (5 ml) was added. The reaction mixture was stirred at 70 C for 20 hours under argon and then poured into water and subsequently extracted with dichloromethane. The combined organic phase was dried (Mg 4 ), filtered and concentrated on celite in vacuum. Dry column chromatography (silica gel μm, eluted with EtAc/Heptane, gradient 0-7% EtAc) afforded 6b. Yield: 1.4 g (73 %), yellow oil. 1 H MR (250 MHz, CDCl 3 ) δ = 8.39 (d, J = 1.3 Hz, 2H), 8.11 (d, J = 1.3 Hz, 2H), 7.90 (s, 2H), (m, 4H), 1.60 (s, 12H), (m, 8H), 0.95 (t, J = 7.0 Hz, 6H). 13 C MR (250 MHz, CDCl 3 ) δ = , , , , , , , , 83.52, 40.62, (2 signals), 23.02, bis(2-methyl-2-hexyl) 2,2'-(benzo[c][1,2,5]thiadiazole-4,7-diyl)bis(5-bromothiophene-3-carboxylate) (7a). To a solution of 6a (964 mg, 1.65 mmol) in 15 ml THF/DMF (1:1) was added B (587 mg,

6 mmol). The resulting mixture was then stirred at room temperature for 24 hours. During this period the reaction was monitored by TLC and additional portions of B (6 x 147 mg) were added until the conversion was complete. The mixture was poured into water and extracted several times with dichloromethane. The combined organic phase was dried (Mg 4 ), filtered and concentrated in vacuum. The crude product was purified by column chromatography (silica gel μm, eluted with dichloromethane/heptane 2:1) and recrystallized from ethanol. Yield: 915 mg (75%), orange solid. Mp = C. 1 H MR (250 MHz, CDCl 3 ) δ = 7.67 (s, 2H), 7.53 (s, 2H), (m, 4H), 1.21 (s, 12H), (m, 8H), 0.83 (t, J = 7.0 Hz, 6H). 13 C MR (250 MHz, CDCl 3 ) δ = , , , , , , , , 83.75, 40.18, 25.89, 25.75, 22.90, bis(2-methyl-2-hexyl) 5,5'-(benzo[c][1,2,5]thiadiazole-4,7-diyl)bis(2-bromothiophene-3-carboxylate) (7b). Prepared with the same procedure as for 7a using the monomer 6b and 2 equivalents of B. Yield: 1.4 g (80 %), orange solid. Mp = C. 1 H MR (250 MHz, CDCl 3 ) δ = 8.11 (s, 2H), 7.74 (s, 2H), (m, 4H), 1.61 (s, 12H), (m, 8H), 0.94 (t, J = 6.9 Hz, 6H). 13 C MR (250 MHz, CDCl 3 ) δ = , , , , , (2 signals), , 84.68, 40.69, (2 signals), 23.03, Polymer T1. 7a (260 mg, 0.35 mmol), 8 (255 mg, 0.35 mmol), Pd 2 dba 3 (15 mg, mmol) and tri-(otolyl)phosphine (41 mg, 0.14 mmol) was mixed in dry degassed toluene (15 ml). The reaction mixture was heated to reflux for 48 hours under argon. After cooling to room temperature the mixture was poured into 150 ml methanol and the polymer was allowed to precipitate. The polymer was filtered 6

7 and purified by oxhlet extraction using methanol, hexane and chloroform. The chloroform phase was concentrated in vacuum and the residue was redissolved in chlorobenzene and precipitated in methanol (1:10). Filtration and drying in vacuum afforded T1. Yield: 165 mg (48 %), dark red solid. 1 H MR (500 MHz, CDCl 3 ) δ = (br, 2H), 7.73 (s, 1H), 7.64 (s, 1H), 7.14 (s, 2H), (br, 8H), 1.56 (s, 6H), 1.27 (s, 12H), (br, 20H), 0.88 (s, 6H), 0.80 (s, 6H), 0.69 (s, 6H). EC (CHCl 3 ): M w = 57700, PDI = 1.9. Polymer T2. Prepared with the same procedure as for T1 using the monomers 7b and 8. Yield: 192 mg (89 %), dark purple solid. 1 H MR (500 MHz, CDCl 3 ) δ = 8.41 (s, 2H), 7.91 (s 2H), 7.59 (s, 2H), 1.98 (br, 8H), 1.64 (s, 12H), 1.58 (s, 6H), 1.44 (br, 8H), (br, 12H), 0.99 (t, J = 7.09 Hz, 6H), 0.81 (t, J = 6.9 Hz, 6H), 0.71 (t, J = 7.3 Hz, 6H). EC (CHCl 3 ): M w = 41600, PDI =

8 1 H- and 13 C-MR pectrum of 2 in CDCl 3 C 4 H 9 2 8

9 1 H- and 13 C-MR pectrum of 3 in CDCl 3 n 3 C 4 H 9 9

10 1 H- and 13 C-MR pectrum of 5 in CDCl 3 C 4 H 9 5 Br 10

11 1 H- and 13 C-MR pectrum of 6a in CDCl 3 11

12 C 4 H 9 C 4 H 9 6a 1 H- and 13 C-MR pectrum of 6b in CDCl 3 12

13 C 4 H 9 C 4 H 9 6b ppm H- and 13 C-MR pectrum of 7a in CDCl 3 13

14 C 4 H 9 C 4 H 9 Br 7a Br 1 H- and 13 C-MR pectrum of 7b in CDCl 3 14

15 C 4 H 9 C 4 H 9 Br 7b Br ppm H-MR pectrum of T1 in CDCl 3 15

16 C 4 H 9 C 4 H 9 n T1 1 H-MR pectrum of T2 in CDCl 3 C 4 H 9 C 4 H 9 n T ppm

17 FTIR spectra of T1 films before heating (black) after heating at 225 C (red) and after heating at 300 C (blue) for 5 min. FTIR spectra of T2 films before heating (black) after heating at 225 C (red) and after heating at 300 C (blue) for 5 min. 17