This project in the Inorganic, Bioinorganic and Organometallic Chemistry Program is concerned with the reaction chemistry of compounds containing metal-metal triple bonds. The structures and reactions of salts of the recently discovered octahalodiosmate(III) anions will be examined with a view to (a) establishing the steric and electronic factors that determine the rotational geometry within the anions and (b) using these compounds as starting materials for the synthesis of various mononuclear and dinuclear osmium compounds. Synthetic strategies will be developed for the preparation of triply-bonded dirhenium(II) complexes which contain bridging sulfur and arsenic ligands. The ability of the triply-bonded dirhenium core to undergo a 4-electron oxidation will be utilized in the conversion of dirhenium phosphine halide complexes into dirhenium polyhydrides and in the reductive coupling of alkyl and aryl nitriles to give metal-imido complexes. These reactions should constitute important synthetic strategies to such classes of compounds. The relationship between dirhenium(II) complexes with rhenium-rhenium triple bonds and hexanuclear trigonal prismatic rhenium(II) cluster compounds will be examined through attempts to synthesize and structurally characterize the latter. Compounds containing metal-metal bonds continue to be of interest as catalysts and as precursors for alloys.
