Oxidative Addition of Silanes to Ru₅(CO)₁₅(μ₅-C) under Photolytic Conditions. The Synthesis and Structural Characterizations of Ru₅(CO)₁₄(SiEt₃)(μ₅-C)(μ-H) and Ru₅(CO)₁₅(SiEt₃)(μ₅-C)(μ-H)

The reaction of Ru5(CO)15(μ5-C), 1, with triethylsilane in the presence of UV−vis irradiation has yielded two new cluster complexes: Ru5(CO)14(SiEt3)(μ5-C)(μ-H), 2, in 11% yield and Ru5(CO)15(SiEt3)(μ5-C)(μ-H), 3, in 4% yield. Compound 2 can be converted to 3 in 89% yield under an atmosphere of CO at 25 °C. Compound 3 is converted back to 2 when heated to 97 °C. Compounds 2 and 3 were both characterized by single-crystal X-ray diffraction analyses. Compound 2 contains a square pyramidal cluster of five ruthenium atoms with a μ5-carbido ligand. The SiEt3 ligand is coordinated to one of the basal ruthenium atoms. The Ru−Ru bond from this ruthenium atom to the apical ruthenium atom is unusually long at 3.1353(8) Å. Compound 3 contains an open Ru5(μ5-C) cluster where one ruthenium atom bridges a butterfly arrangement of four ruthenium atoms. The silyl group is bonded to the bridging ruthenium atom, and the hydride ligand bridges the hinge bond of the butterfly.