Thermal degradation of dimethylvinylarsine in triosmium clusters to give bridging vinyl, vinylidene, and acetylene ligands

Abstract

From the thermal decarbonylation of [Os₃(CO)₁₁{AsMe₂(CHCH₂)}] in refluxing hydrocarbon solvents the new clusters [Os₃(CO)₁₀(CHCH₂)(AsMe₂)], [Os₃H(CO)₉(CCH₂)(AsMe₂)], and [Os₃H(CO)₉(CHCH)(AsMe₂)] have been isolated and shown to be formed successively. The isomerisation of the µ₃-vinylidene to the µ₃-acetylene complex is the first example of this. Structures and dynamic behaviour are discussed mainly on the basis of ¹H n.m.r. data.