Catalyst Design of Novel Nickellacyclic Complexes for Ethylene Polymerization

Azanickelacyclopentene complexes were synthesized and their molecular structures are determined by X-ray crystallographic analysis. These complexes showed good reactivity toward polymerization of ethylene in the presence of pMAO as the cocatalyst to give polyethylene. The effect of increased rigidity of a nickellacycle skeleton and fi xation of iminoacyl moiety in a coordination plane for catalytic activity is discussed. (Received December 7, 2009; accepted February 1, 2010)