Table 2. A comparison of yields of polymer 18 from ROP at various concentrations.

Sample	Conc. (M)	% of 18 (1H NMR spectroscopy)			% Yield of 18 (20 °C) a	% Yield of 18 (–78 °C) a
		24 h	48 h	7 days
18a	1.31	59.8	60.8	59.5	23	65
18b	0.79	41.1	41.8	42.2	b	29
18c	0.44	16.9	25.0	24.3	b	b
18d	0.22	3.17	14.3	14.3	b	b
18e	0.11	10.7	11.6	11.5	b	b

^aTemperature at which the reaction work-up was performed.

^bNo polymer was isolated in this case.