The Cs-Symmetric Aminoboranediyl-Bridged Zirconocene Dichloride [(η-9-C13H8)- BN(iPr)2(η-C5H4)]ZrCl2: Its Synthesis, Structure, and Behavior as an Olefin Polymerization Catalyst

Abstract

The sequential reaction of 9-fluorenyllithium and CpNa with (iPr)2NBCl2 followed by the sequential treatment with LDA and ZrCl4 afforded [(η5-C13H8)BN(iPr)2(η5-C5H4)ZrCl2 (2e). The structure of 2e was determined by X-ray diffraction, which shows that the molecule has Cs symmetry. On activation by excess methylaluminoxane (MAO) 2e was converted to an active catalyst for polymerization of ethylene and propylene. The polypropylene is syndiotactic (81% rr triads).