The ketenylidene route to mixed-metal carbide clusters: [MnRu3C(CO)13]−, [MnOs3C(CO)13]−, [Cr2Ru3C(CO)16]2−, [Mo2Ru3C(CO)16]2−, [Rh3Ru3C(CO)15]−, [Ni3Ru3C(CO)13]2− and [Co3Ru3C(CO)15]−

Redox-condensation reactions between the ketenylidene clusters [M 3 (CO) 9 CCO] 2− (M = Ru, Os) and electrophilic transition-metal reagents provide a convenient route to the new carbido clusters [PPN][MnRu 3 C(CO) 13 ], [PPN][MnOs 3 C(CO) 13 ], [PPN] 2 [Cr 2 Ru 3 C(CO) 16 ], [PPN] 2 [Mo 2 Ru 3 C(CO) 16 ], [PPN][Rh 3 Ru 3 C(CO) 15 ], [PPN] 2 [Ni 3 Ru 3 C(CO) 13 ], and [PPN][Co 3 Ru 3 C(CO) 15 ]. These clusters have been characterized by elemental analysis, IR and variable-temperature 13 C NMR spectroscopy, and, in the case of [PPN][MnOs 3 C(CO) 13 ] and [PPN] 2 [Ni 3 Ru 3 C(CO) 13 ] by single-crystal X-ray diffraction studies. The [MnOs 3 C(CO) 13 ] − cluster consists of a butterfly array of metal atoms with the manganese occupying a hinge position. The structure of the [Ni 3 Ru 3 C(CO) 13 ] 2− is a distorted (opened) octahedron of metal atoms, with the three ruthenium atoms forming one closed face of the octahedron, and the carbide ligand occupying an interstitial site. 13 C NMR data indicate the octahedron closes in solution. For [PPN][MnRu 3 C(CO) 13 ] and [PPN][MnOs 3 C(CO) 13 ], the carbide ligands show variable temperature NMR behavior, which is best interpreted in terms of a two-bond spin-spin coupling of the carbide to the two endo carbonyls on the wingtip Ru or Os atoms. A similar two-bond coupling process may possibly also be operating in the [Cr 2 Ru 3 C(CO) 16 ] 2− cluster.