Rhodium−Germanium Carbonyl Complexes

The compound Rh(CO)4GePh3, 3, was obtained in a high yield (95%) from the reaction of [Rh(CO)2Cl]2 with LiGePh3 under a CO atmosphere. Reaction of 3 with HGePh3 yielded the new dirhodium compound Rh2(CO)6(GePh3)2(μ-GePh2), 4 (55% yield), by a loss of CO and the combination of one equivalent of HGePh3 with two equivalents of 3. Compound 4 contains contains a Rh−Rh bond and a bridging GePh2 ligand formed by cleavage of a phenyl group from a GePh3 ligand. Compound 4 reacts with Pt(PBut3)2 to add a Pt(PBut3) to the Rh−Rh bond to form the compound PtRh2(CO)6(GePh3)2(PBut3)(μ-GePh2), 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.