Bis(cyclopentadienyl)zirconium(III) complexes containing a metal–metal bond: synthesis and properties of zirconium(II) and zirconium(III) complexes

Abstract

The synthesis of dicarbonylbis(cyclopentadienyl)zirconium(II), [Zr(cp)₂(CO)₂](cp =η⁵-C₅H₅), from reductive carbonylation of [Zr(cp)₂(BH₄)₂] in NEt₃ is described in detail. From the reaction of [Zr(cp)₂(CO)₂] with zirconium(IV) derivatives, [Zr(cp)₂X₂](X = Cl or SPh), the first bis(cyclopentadienyl)zirconium(III) derivatives, [{Zr(cp)₂X}₂], have been obtained as dimers containing a zirconium–zirconium bond, accounting for the diamagnetism of the compounds.