Impact of Labile Ligands on Catalyst Initiation and Chain Propagation in Ni-Catalyzed Ethylene/Acrylate Copolymerization
Shuoyan Xiong, Priyabrata Ghana, B.C. Bailey, Heather A. Spinney, Briana S. Henderson, Matthew R. Espinosa, Theodor Agapie
Abstract
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.