Stable borate-bridged ansa-zirconocene complexes. Preparation and X-ray crystallographic characterization of [Cp*2Al]+[Me(Ph)B(η5-C 5H4)2ZrCl2]- and [PPN]+[Cl(Ph)B(η5-C5H4) 2ZrCl2]-

Burns C.T.; Stelck D.S.; Shapiro P.J.; Vij A.; Kunz K.; Kehr G.; Concolino T.; Rheingold A.L.

Abstract

The title complexes are stable, borate-bridged ansa-zirconocene species which have been prepared by reacting [{Ph(SMe2)B(η5-C5H4) 2}ZrCl2] (1) with Cp*2-AlMe and [PPN]Cl. Their molecular structures were determined by X-ray diffraction. Noteworthy are the stabilities of the borate-cyclopentadienyl linkages and the enhanced Lewis acidity of the boron within its strained ansa position.