Oxidatively induced carbon chain growth at a ditungsten centre

Abstract

X-Ray structural and EHMO studies show that two electrons are sequentially removed from a W–W δ* orbital on oxidation of the bis(metallacyclopentadiene) complex [W2(µ-C4Me4)2(η-C5H5)2] to [W2(µ-C4Me4)2(η-C5H5)2]z+(z= 1,2); the dication undergoes C–C coupling and proton loss in boiling MeCN to give [W2(µ-C8Me7CH2)(η-C5H5)2]+ which adds hydride ion to form the metallacyclononatetraene complex [W2(µ-C8Me8)(η-C5H5)2].