SYNTHESIS AND STRUCTURE OF AN ORTHO-METALATED KETAZINE COMPLEX OF OSMIUM, OSH(CO)2[(C6H3-PARA-ME)(PARA-TOLYL)CNNC(PARA-TOLYL)2](PPH3)

Reaction of Os(CO)2(PPh3)2 with a two-fold excess of di-p-tolydiazomethane in benzene at reflux temperature affords the yellow OsH(CO)2[(C6H3-p-Me)(p-tolyl)CNNC(p-tolyl)2](PPh3) (A) in high yield. The structure of A has been determined by X-ray crystallography. The geometry about osmium is octahedral, with the hydride ligand trans to triphenylphosphine and the carbonyl ligands mutually cis. The ketazine ligand is bound to osmium through nitrogen and the ortho-carbon of a p-tolyl group. The OsN and OsC distances are 2.119(5) and 2.100(7) Å, respectively. © 1990.