Preparation of Incomplete Cubane-Type Ru₂M(μ₃-S)(μ₂-Cl)₃ Clusters (M = Sb, Bi) and Isolation of the Ru₂Sb Cluster Having a Novel μ₃-SO Ligand. Functions in Oxygen Atom Transfer and Catalytic Oxidation of PPh₃ to OPPh<sub>

Cubane-type clusters containing Ru and group 15 metal [(Cp∧RuCl)2(μ-SMCl2)2] (2a, M = Bi; 2b, M = Sb; Cp∧ = η5-C5EtMe4) reacted with O2 gas (1 atm) in 1,2-dichloroethane (DCE) at 60 °C to give [(Cp∧RuCl)2(μ-SBiCl2)(μ-Cl)] (3a) for M = Bi and [(Cp∧RuCl)2(μ-SOSbCl2)(μ-Cl)] (4b) for M = Sb, respectively. The latter cluster, consisting of an SO ligand with the novel μ3-κ2S:κO binding mode, was treated with PPh3 in CH2Cl2 at room temperature to be converted into [(Cp∧RuCl)2(μ-SSbCl2)(μ-Cl)] (3b) with concurrent generation of OPPh3. It has been demonstrated that 3b catalyzes the oxidation of PPh3 into OPPh3 in DCE at 60 °C under O2 (1 atm). Similar activity as the catalyst for oxygenation of PPh3 by O2 has also been observed for 3a. An X-ray diffraction study was undertaken to determine the detailed structures for 3a,b and 4b.