Table 1. GPC Characterization Data for Isolated Polyaminoborane^a.

entry	catalyst	[Rh]TOT, mol %	conditions	Mn, g/mol	Đ
1	2a	1	open (Ar flow)	6400	1.8
2	2a	0.4	open (Ar flow)	29500	1.8
3	2a	0.2	open (Ar flow)	34900	1.5
4	2a	0.1	open (Ar flow)	34600	1.7
5	2a	0.1	H2 measurement	29400	1.6
6	2a	0.2	H2 measurement	14500	1.7
7	2a	0.4	H2 measurement	10100	1.8
8	2a	1	H2 measurement	5500	1.8
9	3a	0.4	H2 measurement	14800	1.6
10	4b	0.4	H2 measurement	15900	1.8
11	2a	0.4	H2 measurement/1 equiv of H3B·THF/50 μL of THF	6600	1.9
12	2a	0.4	H2 measurement/10 equiv of [H2B(NMeH2)2][BArF4]	2800	2.3
13	2a	0.4	H2 measurement/50 μL of THF	11000	1.6
14	2a	0.4	H2 measurement/∼2 equiv of NMeH2 in 50 μL of THF	27400	1.6
15	2a	0.4	open/∼2 equiv of NMeH2 in 50 μL of THF	32100	1.6
16	5/6	0.2	H2 measurement	38900	1.6
17	5/6	0.4	H2 measurement	33200	1.6
18	5/6	1	H2 measurement	20600	1.5
19	6	0.8	H2 measurement	22500	1.5
20	2a	0.2	H2 measurement/∼2 equiv of NMeH2 in 50 μL of THF	34800	1.5
21	A9	0.2	H2 measurement	40500	1.7
22	A9	0.2	H2 measurement/∼2 equiv of NMeH2 in 50 μL of THF	61900	1.6
23	C16	0.2	H2 measurement	63100	1.7
24	C16	0.2	H2 measurement/∼2 equiv of NMeH2 in 50 μL of THF	78900	1.6

^aAll at 298 K, 0.223 M H₃B·NMeH₂, 1,2-F₂C₆H₄ solvent. GPC data quoted relative to polystyrene standards (calibrated between 500 and 480 000 g/mol), triple column, RI detection, THF with 0.1 w/w% [NBu₄]Br, 35 °C, sample concentration = 2 mg/cm³. Open conditions: periodic sampling by ¹¹B NMR spectroscopy determined end point (e.g., 6 h for entry 4). Under H₂ measurement conditions, the reaction was stopped when there was no significant change in H₂ evolved.