-MU(4)-CO)(2)(MU-CO)(CO)(12)(ETA(5)-C(5)R(5))](R=H OR ME) - SYNTHESES, X-RAY STRUCTURES AND SPECTROSCOPIC CHARACTERIZATION

The reaction of [Ru-3(CO)(12)] (1) with nickelocene, Ni(Cp)(2) (used a s a source of Cp for the first time in the cluster chemistry) under re flux in n-heptane or with pentamethylcyclopentadiene in n-octane yield ed novel thermally stable hexaruthenium clusters (2)-mu(4)-CO)(2)(mu-C O)(CO)(12)(eta(5)-C(5)R(5))], where R = H (2) or R = Me (3). Their str uctures have been determined by X-ray diffraction and characterized by IR, H-1, C-13 NMR and mass spectroscopy. A C-13 NMR spectral assignme nt is reported for the first time for the cluster (3) characterized by a tetrahedral Ru-4 arrangement with two edge-bridging Ru-atoms contai ning 15 CO groups and an eta(5)-Cp-ligand.