The invention provides a novel metal complex which, when used with an activating cocatalyst, provides a novel catalyst composition. The invention also provides a polymerization method which utilizes the catalyst composition to produce polymers and copolymers containing polar monomer groups. More specifically, the invention comprises a composition comprising the formula LMXZn wherein X is selected from the group consisting of halides, hydride, triflate, acetates, borates, C1 through C12 alkyl, C1 through C12 alkoxy, C3 through C12 cycloalkyl, C3 through C12 cycloalkoxy, aryl, thiolates, carbon monoxide, cyanate, olefins, and any other moiety into which a monomer can insert. M is selected from the group consisting of Cu, Ag, and Au. L is a nitrogen-containing bidentate ligand having more than two nitrogen atoms. Z is a neutral coordinating ligand and n equals 0, 1, or 2.