Synthesis of <i>ansa</i>-Zirconocene/Rhodium Heterobimetallic Complexes:  Enhanced Catalytic Activity in Stereospecific Polymerization of α-Olefins

Abstract

Novel heterobimetallic complexes that consist of zirconium and rhodium, LRh(η2-CH2CH)2Si(η5-C5H2-2,4-Me2)2ZrCl2 (3a L = η5-C9H7, 3b η5-C5H5, 3c η5-C5Me5), were synthesized, and 3b was structurally characterized. The complexes have a “C2-symmetric” ansa-zirconocene part and the rhodium metal on the bridge part. The complexes 3a−c in combination with methylaluminoxane catalyzed highly isospecific polymerization of α-olefins. Their catalytic activities were higher than that of the parent zirconocene complex, and the obtained polymer had a larger molecular weight