Impact of Labile Ligands on Catalyst Initiation and Chain Propagation in Ni-Catalyzed Ethylene/Acrylate Copolymerization

Polar polyolefin synthesis by coordination polymerization
is of
high interest, but the catalysts’ low activity limits industrial
implementation. Herein, we demonstrate how the nature of the labile
ligand, L, impacts the performance of neutral nickel catalysts supported
by bidentate phosphine-phenoxide and phosphine-enolate ligands in
ethylene/acrylate copolymerization. By tuning L, the copolymerization
activity reaches ∼24000 kg/(mol h). In situ studies indicate that a weaker L leads to faster chain propagation
and more efficient catalyst initiation. Overall, this work highlights
the potential of a strategy to improve catalyst activity in polar
polyolefin synthesis complementary to design optimization for the
bidentate ligand.