The relative stability of cyclo-octatetraene complexes of zirconium(II) and zirconium(IV); X-ray crystal structure of [Zr(η-C3H5)(η-C3Me5)-(1–4-η-C8H8)]

Abstract

Reaction of [ZrCl(η-C₈H₈)(η-C₅Me₅)](1) with MR (M = MgCl or Li; R = n-alkyl, aryl, vinyl, acetylide and substituted allyl) affords the yellow zirconium(IV) species [ZrR(η-C₈H₈)(η-C₅Me₅)](2) whereas Mg(Cl)-(CH₂–CHCH₂) gives the purple-black complex (3) shown by X-ray crystallography to be [Zr(η-C₅H₅)(η-C₃Me₅)(1–4-η-C₈H₈)], formally a derivative of zirconium(II).