Complexes of mid-transition metals and unsaturated nitrogenous ligands as single-site catalysts

摘要

Novel compounds are provided which are useful as catalysts, particularly in the polymerization of addition polymerizable monomers such as olefinic or vinyl monomers. The compounds are complexes of a mid-transition metal coordinated to at least two ligands, at least one of which is an unsaturated nitrogenous ligand. Depending on ligand substitution, stereospecific catalysts can be provided, including isospecific catalysts and syndiospecific catalysts. Catalyst systems containing the novel compounds in combination with a catalyst activator are provided as well, as are methods of using the novel compounds in the preparation of polyolefins.