Co-ordinative addition reactions to bis(η-cyclopentadienyl)vanadium(II) and to the bis(η-cyclopentadienyl)vanadium(III) cation: carbonyl, iso-cyanide, olefin, and phosphine derivatives

Abstract

The co-ordinative addition of π-acid ligands to [V(cp)₂](cp =η-cyclopentadienyl) gives the new vanadium complexes. [V(cp)₂L](L = CO, 2,2′-bipyridyl, CS₂, or activated olefins). Reduction of [V(cp)₂(CO)] under mild conditions gives [V(cp)(CO)₄]. The generation and co-ordination ability of the titanocene-like [V(cp)₂]⁺ is explored. It is a quite reactive species toward ligands (L) such as CO, phosphines, and RNC, giving [V(cp)₂L₂][BPh₄] complexes. An unusual carbonylation of an aqueous solution of [V(cp)₂]⁺ gives [V(cp)₂(CO)₂]⁺.