Supporting Information

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1 Supporting Information Wiley-VCH Weinheim, Germany

2 Iridium-Catalyzed Dehydrocoupling of Primary Amine-Borane Adducts: A Route to High Molecular Weight Polyaminoboranes, Boron-Nitrogen Analogues of Polyolefins Anne Staubitz, Alejandro Presa Soto, Ian Manners*

3 Supporting Information Experimental Section Reactions were performed under nitrogen or argon using dry solvents. IR spectra were measured using a Perkin Elmer FT-IR spectrometer. NMR experiments were performed on JEOL ecp300 and ecp400 spectrometers in dry solvents. GPC chromatograms were recorded on a Viscotek VE2001, using a flow rate of 1 ml / min in THF with 0.1 w/w % n-bu 4 NBr, calibrated for polystyrene standards. Dynamic light scattering experiments were performed using a Malvern spectrometer in a quartz cuvette using THF or DMSO (not dried) at 20 ºC, citing the size-psd values. TGA was run on a TGA Q500 apparatus at 10 ºC / min. For powder X-ray diffraction of the thermal decomposition product of polyamino-borane 2g, a larger quantity of compound was used. This was obtained by heating polyaminoborane in a Carbolite tube furnace at 10 ºC / min to 900 ºC. Powder X-ray diffraction was measured on a Bruker D8 Advance diffractometer. SEM was was run on a JEOL JSM 6330F apparatus. Poly(N-methylaminoborane) 2a The synthesis of this material is described as a representative example. N-Methylamine-borane (224 mg, 5 mmol) was suspended in THF (0.3 ml) and cooled to 0 ºC. Then the catalyst (9 mg, 15 µmol) was added as a solution in THF (0.2 ml). Immediate bubbling ensued. After 2 mins at this temperature, the cooling bath was removed and the reaction mixture was allowed to stir for 20 min to 1 h at rt. Then THF (3 ml) was added and the reaction mixture precipitated into n-butane (approx 12 ml) at -78 ºC. The mixture was filtered in order to remove n-butane at low temperature giving the polymer as a white powder, which was dried overnight under vacuum (60 %, m = 129 mg, corrected for residual THF = 10%). Evaporation of the filtrate left a reddish-brown residue that was still catalytically active when treated with a solution of ammonia-borane in THF. The polymer can also be purified by precipitation into hexanes at -78 ºC. 1 H-NMR (400 MHz, CDCl 3 ): = 2.75 (1H, NH), 2.18 (3H, CH 3 ), 1.68 (2H, BH 2 ) ppm; 11 B{ 1 H}-NMR (160 MHz, CDCl 3 ): -6.7 ppm; 13 C-NMR (100 MHz, CDCl 3 ): = 36.8 (br), 35.8 ppm; FT-IR: 3256 (N-H), 2985 (C-H), 2366 (B-H) cm -1 ; elemental analysis calcd for CH 6 NB, corrected for 10 % (w/w) of THF detected by NMR: C 31.9, H 13.9, N 29.4; found C 30.5, H 13.8, N 28.2; GPC Mw = 160,000, PDI 2.9; DLS (THF) 3 nm; TGA: Major decomposition temperature: 180 ºC (inflection point 164 ºC), ceramic yield: 18% at 180 ºC. Key data for 2b-2i 2b: 1 H-NMR (400 MHz, CDCl 3 ): = (m, 5H, 3 NH, N H 2 ), 2.20 (s, 9H, 3 CH 3 ), ppm (m, 8H, BH 2 B H 2 ); 11 B{ 1 H}-NMR (160 MHz, CDCl 3 ): -9.0 ppm; 13 C-NMR (100 MHz, CDCl 3 ): = 35.9 (br), 35.8 ppm; FT-IR: 3256 (N-H), 2985 (C-H), 2366 (B-H) cm -1 ; elemental analysis calcd for C 3 H 22 N 4 B 4, corrected for 12 % (w/w) of THF: C 28.1, H 13.0, N 31.3; found C 28.1, H 13.2, N c: 1 H-NMR (400 MHz, CDCl 3 /DMSO-d 6 1/1): = (m, 3H, NH, N H 2 ), 1.53 (s, 3H, CH 3 ), (m, 4H, BH 2, B H 2 ); 11 B{ 1 H}-NMR (160 MHz, CDCl 3 ): ppm; 13 C-NMR (100 MHz, CDCl 3 /DMSO-d 6 1/1): = 34.7 (br) ppm; FT-IR: 3252 (N-H), 2984 (C-H), 2366 (B-H) cm -1 ; elemental analysis calcd for CH 10 N 2 B 2, corrected for 15 % (w/w) of THF: C 24.23, H 13.6, N 32.2; found C 23.9, H 13.9, N d: 1 H-NMR (400 MHz, C 6 D 6 ): = 3.15 (1H, NH), (m, 6H, 2 CH 2, BH 2 ), (m, 2H, CH 2 ), 0.96 (t, J = 7.14 Hz, 3H, CH 3 ); 11 B{ 1 H}-NMR (160 MHz, C 6 D 6 ): -7.7 ppm; 13 C-NMR (100 MHz, C 6 D 6 ): = 51.1 (br), 30.4, 20.9, 13.9 ppm; FT-IR: 3249 cm -1 (N-H), 2958 cm -1 (C-H), 2395 (B-H) cm -1 ; elemental analysis calcd for C 4 H 12 NB: C 56.6, H 14.2, N 16.5; found C 53.7, H 15.0, N 13.4, no residual solvent detected by NMR. This polymer was purified by filtration through a plug of alumina. 2e: 1 H-NMR (400 MHz, CDCl 3 ): = (m, 27H, 3 NH, N H, 3 BH 2, B H 2, N CH 3, 6 CH 2 ), 1.29 (app s (br), 6H, 3 CH 2 ), 0.91 (app s (br), 9H, 3 CH 3 ) ppm; 11 B{ 1 H}-NMR (160 MHz, CDCl 3 ): -7.1 ppm; 13 C-NMR (100 MHz, CDCl 3 ): = 50.6 (br), 36.3 (br), 30.1, 20.8, 14.0 ppm; FT-IR: 3257 (N-H), 2959 (C-H), 2393 (B-H) cm -1 ; elemental analysis calcd for C 13 H 42 N 4 B 4 : C 52.4, H 14.2, N 18.8; found C 50.2, H 14.5, N 18.9, no residual solvent detected by NMR. 2f: 1 H-NMR (400 MHz, CDCl 3 ): = (m, 13H, NH, N H, BH 2, B H 2, N CH 3, 2 CH 2 ), (m, 2H, CH 2 ), 0.91 (t, J = 6.87 Hz, 3H, CH 3 ) ppm 11 B{ 1 H}-NMR (160 MHz, CDCl 3 ): -7.7 ppm; 13 C-NMR (100 MHz, CDCl 3 ): = 50.4 (br), 36.2 (br), 30.2, 20.7, 14.0 ppm; FT-IR: 3256 (N-H), 2958 (C-H), 2390 (B-H) cm -1 ; elemental analysis calcd for C 5 H 18 NB: C 47.0, H 14.2, N 21.9; found C 45.6, H 14.4, N 22.1, no residual solvent detected by NMR. 2g: insoluble material. FT-IR: 3299, 3248 (N-H), 2356, 2312 (B-H) cm -1 ; elemental analysis calcd for H 4 NB: N 48.6 H 14.0; found N 44.0 H 13.1; C 4.9 from residual solvent. 2h: insoluble material. FT-IR: 3296, 3248 (N-H), 2355, 2312 (B-H) cm -1 ; elemental analysis calcd for H 42 N 11 B 11 : N 48.9, H 13.4 C 0.0; found N 47.7, H 13.3; C 2.7 from residual solvent. 2i: insoluble material. FT-IR: 3217 (N-H), 2442 (B-H) cm -1. 1

4 Additional Information NMR: By using 2-D NMR techniques the signals in the 13 C-NMR were unambiguously assigned using HSQC (Figure 1) and HMBC methods (Figure 2) for copolymer 2e. Figure 1. HSQC-Dept of copolymer 2e. Figure 2. HMBC of coplymer 2e. WAXS: We analysed the polyaminoborane 2g by WAXS. When the result was compared to the XRD pattern of the isoelectronic polyethylene in semicrystalline form (approximately 2 = 21º, d-spacing 4.2 Å), 1 we found that the unit cell of our material was smaller (2 = º, d-spacing 3.6 Å). 1 S. Krimm, J. Phys. Chem. 1953, 57, 22. 2

5 SEM: The pellet obtained after the pyrolysis of polyaminoborane 2b was frozen in liquid nitrogen and cracked with a blunt instrument before visualising one of the exposed surfaces by SEM. The material has relatively homogeneous appearance and no evident porosity. 3