Reaction of Alkenylzirconocenes with Dialkylzirconocenes:  Unexpected Formation of Bimetallic (μ-Alkynyl)zirconocene Complexes

Reaction of alkenylzirconocenes Cp2ZrX(MeCCH2) (X = Cl, Br) with dialkylzirconocenes Cp2ZrR2 (R = Me, Et, Bu) yielded the unexpected bimetallic zirconocene complexes Cp2Zr(μ-X)(μ-C⋮CCH3)ZrCp2 (X = Cl, Br). Its structure (X = Cl) was determined by X-ray crystallography. The monitoring of the reaction of Cp2ZrBu2 with Cp2ZrBr(MeCCH2) revealed that the first step of this reaction was an exchange reaction of the Bu and Br groups.