Cluster Synthesis. 10. Reaction of Os₃(CO)₁₀(μ₃-S) with Trimethylamine N-Oxide Dihydrate. Syntheses and Structural Characterizations of Os₃(CO)₈(NMe₃)(μ-OH)(μ₃-S)(μ-H) and the Six-Atom-Chain Cluster Os₆(CO)₁₈(μ-OH)(μ₄-S)(μ₃-S)(μ-H)

The reaction of Os₃(CO)₁₀(μ₃-S) with 2 equiv of Me₃NO·2H₂O leads to the formation of the compound Os₃(CO)₈(NMe₃)(μ-Oh)(μ3-S)(μ-H) (1) in 44% yield. Compound 1 was characterized by IR and ¹H NMR spectroscopies and by a single-crystal X-ray diffraction analysis. For 1 the space group is PI, a = 9.703 (1) Å, b = 13.269 (2) Å, c = 8.057 (1) Å, α = 105.78 (1)°, β = 102.61 (1)°, γ = 77.80 (1)°, Z = 2, and p_calcd = 3.12 g/cm³. The molecule consists of an open cluster of three osmium atoms with bridging hydroxyl and hydrido ligands, a triply bridging sulfido ligand, and one trimethylamine ligand. Compound 1 can be reacted with Os₃(CO)₁₀(μ₃-S) to give the hexanuclear cluster Os₆(CO)₁₈(μ-OH)(μ₄-S)(μ₃-S)(μ-H) (2) in 43% yield. Compound 2 was characterized by IR and ¹H NMR spectroscopies and by a single-crystal X-ray diffraction analysis. For 2 the space group is PI with a = 12.127 (3) Å, b = 14.009 (6) Å, c = 9.155 (3) Å, α = 103.24 (3)°, β = 98.18 (2)°, γ = 90.00 (3)°, Z = 2, and P_caicd = 3.83 g/cm³. Compound 2 consists of a chain of six osmium atoms connected by Five osmium-osmium bonds. It also contains a quadruply bridging sulfido ligand, a triply bridging sulfido ligand, a bridging hydroxyl ligand, and a bridging hydrido ligand. The resonances of the protons on the hydroxyl ligands in both 1 and 2 are shifted upfield from Me₄Si.