A traditional synthetic method, and a new structural motif, for molybdenum-gold clusters: synthesis and solid-state structure of a Au8[Mo(CO)5)4(PPh3)4

The neutral cluster [Au8Mo4(CO)(20)(PPh3)(4)] was synthesized in low yield from [AuCl(PPh3)] and [Mo-2(CO)(10)](2-) in acetonitrile at room temperature. The cluster was characterized by X-ray analysis, IR, and P-31 NMR spectroscopy. Its solid-state structure consists of four Au3Mo tetrahedral units, fused by four Au atoms in a ring. The average bond lengths are Au-Au 2.77 angstrom and Mo-Au 2.93 angstrom. The internal angles of the planar square ring are very close to 90 degrees