SYNTHESIS AND X-RAY STRUCTURE OF THE CARBIDO-OXO CLUSTER MO2RU4(MU(6)-C)(MU-O)(CO)(12)CP(2)

The unusual heterometallic carbido-oxo cluster Mo2Ru4(mu(6)-C)(mu-O)(C O)(12)Cp(2) (Cp = eta-C5H5) has been isolated in moderate yield from t he reaction of Mo-2(CO)(4)-Cp(2) with Ru-3(CO)12 in refluxing toluene. The X-ray crystal structure of the complex unexpectedly reveals the p resence of two isomeric molecules in the unit cell: both have octahedr al metal cores with a carbon atom in the center and an oxo ligand brid ging the molybdenum-molybdenun bond, but one molecule has two bridging carbonyl ligands on. Mo-Ru edges whereas the other has two additional carbonyls weakly semibridging Ru-Ru edges.