Systematic synthesis of hexanuclear clusters from pentanuclear clusters; crystal structure of [Os6H2(CO)19], a hexanuclear metal carbonyl cluster with a terminal hydride ligand

Abstract

Reaction of [Os₅(CO)₁₆] with Me₃NO in MeCN gives [Os₅(CO)₁₅(MeCN)], which on reaction with [OsH₂(CO)₄] undergoes an increase in nuclearity to give two new hexaosmium species (1) and (2); X-ray structure analysis established that (1) is [Os₆H₂(CO)₁₉] with a ‘spiked’ trigonal bi-pyramidal structure which, in boiling toluene, rearranges to give the known capped square-pyramidal molecule [Os₆H₂(CO)₁₈] with loss of CO.