Carbon–hydrogen bond activation of phenyldi(2-thienyl)phosphine at a triosmium cluster centre

The phenyldi(2-thienyl)phosphine (PhPTh2) complexes [Os3(CO)12−n(PhPTh2)n] (n = 1–3) (1–3) have been prepared. Thermolysis of 1 and either 2 or 3 in octane affords carbon–hydrogen bond activation products [Os3(CO)9{μ3-PPhTh(C4H2S)}(μ-H)] (4) and [Os3(CO)8(PPhTh2){μ3-PPhTh(C4H2S)}(μ-H)] (5), respectively. Both exist as isomeric mixtures differing in the relative positions of phenyl and thienyl substituents with respect to the triosmium centre. The nature of the process has been confirmed by a single crystal X-ray diffraction analysis of 4.