Cationic Zirconocene Hydrides: A New Type of Highly Effective Initiators for Carbocationic Polymerizations

Abstract

The reaction of [CPh3][B(C6F4R)4] with [Cp‘2ZrH2]2 (Cp‘ = C5H4SiMe3) gives the new binuclear hydrido complexes [Cp‘4Zr2H3][B(C6F4R)4] (R = F, SiPri3), which are highly active initiators for the polymerization of isobutene and isobutene−isoprene copolymerizations at near-zero concentrations of ionizing solvents. The structure of the trinuclear hydride [Cp‘5(η1:η5-C5H3SiMe3)Zr3H4]+[B(C6F4SiPri3)4]- is reported.