SYNTHESIS OF A HEPTANUCLEAR RHENIUM-IRIDIUM CARBIDO CARBONYL CLUSTER AND OF (TRIPHENYLPHOSPHINE)GOLD(I)DERIVATIVES

The octanuclear cluster [Re5Ir(mu(6)-C)(CO)(17)(mu(3)-Re(CO)(3))(2)](2 -) loses a [Re(CO)(3)](+ )capping unit in refluxing acetonitrile to gi ve the heptanuclear cluster [Re5Ir(mu(6)-C)(CO)(17)(mu(3)-Re(CO)(3))]( 3-) The latter compound can be capped with [AuPPh3](+) groups to form the monogold and digold derivatives [Re6Ir((CO)(20)(AuPPh3)](2-) and [ Re6IrC(CO)(20)(AuPPh3)(2)](-). These three new anionic clusters have b een isolated as PPN+ and/or PPk(4)(+) salts and are formulated on the basis of microanalytical and FAB mass spectrometric data. The solid-st ate structure of [PPh4][Re6Ir(mu(6)-C)(CO)(20)(mu 3-AUPPh(3))(2)]. CH2 Cl2 has been determined by X-ray diffraction. Crystal data: triclinic, space group P (1) over bar, a 13.1182(1) Angstrom, b = 15.1806(1) Ang strom, c = 23.4061(3) Angstrom, alpha = 74.251(1)degrees, beta = 82.05 8(1)degrees, gamma = 70.306(1)degrees Z = 2. Further information on th e structures of the compounds in solution has been derived from C-13 a nd P-31 NMR studies.