Osmium−Bismuth Complexes from the Reaction of Os₃(CO)₁₁(NCMe) with BiPh₃

Five new compounds were obtained from the reaction of Os3(CO)11(NCMe), 1, with BiPh3 in hexane solution at reflux. These have been identified as Os2(CO)8(μ-BiPh), 2, Os(CO)4Ph2, 3, Os4(CO)14(μ-η3-OCC6H5)(μ4-Bi), 4, Os4(CO)15Ph(μ4-Bi), 5, and Os5(CO)19Ph(μ4-Bi), 6. Cleavage of the phenyl groups from the BiPh3 was the dominant reaction pathway. Fragmentation of the original triosmium cluster was accompanied by reaggregation processes that were facilitated by the naked bismuth to yield the higher nuclearity osmium cluster complexes containing spiro-bridging bismuth ligands. Compound 6 was photo-decarbonylated to yield the compound HOs5(CO)18(μ-η2-C6H4)(μ4-Bi), 7, formed by ortho-CH activation of the σ-bonded phenyl ring in 6 to form a bridging η2-benzyne ligand. Compounds 2− 7 were each characterized structurally by a single-crystal X-ray diffraction analysis.