New µ-methylene-dicobalt complexes and evidence for µ-methylene to terminal methylene transformations

Abstract

New µ-alkylidene complexes [CO₂(CO)₄(µ-CHR)(µ-dppm)] and [Co₂(CO)₄(µ-CH₂)(µ-CHR)(µ-dppm)], R H or CO₂Et, dppm = Ph₂PCH₂PPh₂, have been prepared by displacement of µ-CO groups from [CO₂(CO)₄(µ-CO)₂(µ-dppm)]on reaction with CHRN₂; dynamic n.m.r. data indicate rapid µ-CH₂ to terminal methylene transformations in these complexes.