Structural characterization of [Ru3Mo(μ3-η1-CC}(μ-CO)3(CO)2(η-C5H5)5]: a revisitation

A re-examination, crystallographically, of the structure of [MoRu3C2(CO)5(η-C5H5)4] by low temperature single crystal X-ray studies of two forms, one the previously recorded tetragonal P4/m dichloromethane solvate, and the other an un-solvated monoclinic P21/c phase, is recorded, being undertaken in an attempt to establish with greater certainty by such means the disposition of the molybdenum atom among the [M3(triangle)+M(pendant)] metal atom complement. The revised interpretation converges on [μ3-η1-{(η-C5H5)(CO)2MoC–C}Ru3(CO)5(η-C5H5)3] which ensures that the cluster is electron precise.The reinvestigation of the single crystal X-ray structural determination of the product of the reaction between [{Ru(CO)2(η-C5H5)}2(μ-CC)] and [Mo2(CO)4(η-C5H5)2] has confirmed the stoichiometry but the connectivity has been reformulated. While it was previously modelled with a Ru(CO)2(η-C5H5) group pendant, in the revised structure, now Mo(CO)2(η-C5H5) is pendant. The new formulation better fits the available spectroscopic data.