Late transition metal complex catalysts for olefin polymerization

This review summarizes the recent developments in the field of olefin polym erization, especially focuses on the topic by nickel, palladium, iron, coba lt, and ruthenium complex catalysts including the brief summary of this res earch background. A lot of studies have been explored concerning olefin pol ymerization by nickel and palladium complex catalysts especially after the discovery of a-diimine coordinated nickel and palladium catalysts reported by Brookhart et al., and these results introduce new possibilities for maki ng new type of olefin-based copolymers by these catalysts. In particular, r ecent discovery concerning ethylene polymerization by iron and cobalt compl exes containing 2,6-bis(imino)pyridine ligand attracted particular attentio n due to the exceptionally high catalytic activity, and the contents concer ning this topic have also been summarized briefly. We also wish to introduc e our recent results concerning olefin polymerization by ruthenium and iron complexes-cocatalyst systems.