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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]−

1990; Elsevier BV; Volume: 394; Issue: 1-3 Linguagem: Inglês

10.1016/0022-328x(90)87229-7

1872-8561

Michael P. Jensen, William Henderson, Dean H. Johnston, Michal Sabat, Duward F. Shriver,

Boron Compounds in Chemistry

Redox-condensation reactions between the ketenylidene clusters [M3(CO)9CCO]2− (M = Ru, Os) and electrophilic transition-metal reagents provide a convenient route to the new carbido clusters [PPN][MnRu3C(CO)13], [PPN][MnOs3C(CO)13], [PPN]2[Cr2Ru3C(CO)16], [PPN]2[Mo2Ru3C(CO)16], [PPN][Rh3Ru3C(CO)15], [PPN]2[Ni3Ru3C(CO)13], and [PPN][Co3Ru3C(CO)15]. These clusters have been characterized by elemental analysis, IR and variable-temperature 13C NMR spectroscopy, and, in the case of [PPN][MnOs3C(CO)13] and [PPN]2[Ni3Ru3C(CO)13] by single-crystal X-ray diffraction studies. The [MnOs3C(CO)13]− cluster consists of a butterfly array of metal atoms with the manganese occupying a hinge position. The structure of the [Ni3Ru3C(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. 13C NMR data indicate the octahedron closes in solution. For [PPN][MnRu3C(CO)13] and [PPN][MnOs3C(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 [Cr2Ru3C(CO)16]2− cluster.