Rhodium-germanium carbonyl complexes.

The compound Rh(CO)(4)GePh(3), 3, was obtained in a high yield (95%) from the reaction of [Rh(CO)(2)Cl](2) with LiGePh(3) under a CO atmosphere. Reaction of 3 with HGePh(3) yielded the new dirhodium compound Rh(2)(CO)(6)(GePh(3))(2)(mu-GePh(2)), 4 (55% yield), by a loss of CO and the combination of one equivalent of HGePh(3) with two equivalents of 3. Compound 4 contains contains a Rh-Rh bond and a bridging GePh(2) ligand formed by cleavage of a phenyl group from a GePh(3) ligand. Compound 4 reacts with Pt(PBu(t)(3))(2) to add a Pt(PBu(t)(3)) to the Rh-Rh bond to form the compound PtRh(2)(CO)(6)(GePh(3))(2)(PBu(t)(3))(mu-GePh(2)), 5 (42% yield). Fenske-Hall molecular orbitals were calculated for compounds 4 and 5 to explain the nature of the metal-metal bonding in these compounds. Compounds 3-5 were fully characterized by IR, NMR, and single-crystal X-ray diffraction analyses.