Influence of the Steric Demand of Coligands on the Catalytic Activity of Nickel(II) Complexes in the Copolymerization of Ethene and Carbon Monoxide

Table 1

³¹P{¹H} NMR shifts in ppm of the ligands and the synthesized precursor and catalyst complexes in C₆D₆.

P-ligand		[NiBrMes(PR^aR^bR^c)2]		[Ni(L)MesPR^aR^bR^c]
PPh3	−4.5	2b	21.0 [17]	K2	24.8 [17]
PnBuPh2	−14.8	3b	14.5	K3	18.9
PnBu2Ph	−23.1	4b	6.5	K4	11.9
PnBu3	−29.6	5b	3.5	K5	10.4
P(OEt)3	139.9	6b	111.2	K6	105.0
PCyPh2	−2.6	7b	21.1	K7	28.0