ROP of rac-LA catalysed by complexes 1–4, [BnONa], [BnOK] and [LZn2OBn]^a.

Entry	Cat.	Time (min)	Conv.b (%)	M n,obs c (Da)	M n,calc d (Da)	Đ c
1e,f	3	2.5	12	—	—	—
2	3	0.33	47	2100	3400	1.3
3	3	2.5	71	3000	5100	1.2
4	3	7.5	86	3900	6200	1.4
5ef	4	2.5	13	—	—	—
6	4	0.08	45	1900	3300	1.7
7	4	0.33	60	2500	4300	1.4
8	4	1.25	81	3900	5800	1.4
9	4	2	93	4300	6700	1.4
10e	1	1.25	79	14 800	11 400g	4.1
11e	[BnONa]	1.25	88	20 400	12 700g	2.7
12e	2	0.33	72	7300	10 400g	4.3
13e	[BnOK]	0.25	94	13 100	13 600g	1.9
14e	[LZn2OBn]	7.5	17	—	—	—
15e,h	[BnOK] + [LZn2OBn]	0.25	99	8300	7100	1.6

^a100 : 1 : 2 LA : cat : BnOH, [LA] = 1 M in THF.

^bCalculated using ¹H NMR spectroscopy.

^cDetermined by GPC using polystyrene standards in THF. Values corrected by Mark–Houwink factor (0.58).³¹

^dCalculated from the monomer conversion M_n,calc = M₀ × ([M]/[I]) × conversion assuming 2 chains per catalyst.

^eNo BnOH used.

^fPolymerisations run at 60 °C.

^gCalculated from the monomer conversion M_n,calc = M₀ × ([M]/[I]) × conversion assuming 1 chain per catalyst.

^h [BnOK] generated in situ from KH and BnOH before adding [LZn2OBn].