Methylidene and hydrazone complexes of the cluster family: Cp′3M3(CO)2(CH2) (M=Co, Rh, Ir)

The reactions of diazoalkanes and trinuclear complexes of the form Cp′M(CpCo)2(CO)2 are described where Cp′ is one of several types of cyclopentadienyl ligands and M is either Co, Rh and Ir. Two types of products which preserve the trinuclear cluster skeleton are formed: the methylidene complex, reflecting loss of dinitrogen and incorporation of the methylidene ligand, and the hydrazone complex where incorporation of the intact diazoalkane occurs. NMR and X-ray structural investigations define the general and specific structural elements of these two product types. More detailed NMR investigations have been used to monitor the dynamic behavior of the methylidene ligand in these complexes. In several instances both degenerate and nondegenerate movement of this ligand in concert with the carbonyl ligands is observed.