Synthesis of Semibridging μ-Vinylidene Titanium−Copper and −Gold Complexes. Crystal and Molecular Structure of Cp*2Ti(Cl)(μ-CCH2)AuPPh3

Abstract

The titanocene−vinylidene intermediate [Cp*2TiCCH2] (1; Cp* = C5(CH3)5), formed by methane elimination from Cp*2Ti(CHCH2)(CH3) (2), reacts with group 12 LM‘X complexes ([Me3PCuCl]4 (4a), [Ph3PCuCl]4 (4b), [i-Pr3PCuCl]4 (4c), [Me3PCuC⋮CPh]4 (4d), [Ph3PAuCl] (4e) (Ti:M‘ = 1:1)) to give heterodinuclear μ-vinylidene compounds Cp*2Ti(X)(μ-CCH2)M‘L (5a−e). The molecular structure of 5e was determined by X-ray diffraction analysis, which revealed a titanium−gold bond asymmetrically bridged by the vinylidene ligand. A semibridging bonding mode for the CCH2 group in the new complexes is indicated by NMR spectroscopic and X-ray diffraction data.