Recent advances in the chemistry of Group 4 metal complexes incorporating [OSSO]-type bis(phenolato) ligands as post-metallocene catalysts

Abstract

Several recent efforts concerning post-metallocene Group 4 metal complexes incorporating mixed donor [OSSO]-type tetradentate bis(phenolato) ligands are reviewed. These [OSSO]-type ligands can be mainly classified as 5–5–5, 5–6–5 and 6–5–6 arrays of chelate rings toward central metals. As the main topics are described the design and unique coordination chemistry of the [OSSO]-type ligands and catalytic activities of the resultant titanium, zirconium, and hafnium complexes as single-site catalysts for polymerizations and copolymerizations of olefins.