Reaction of tri(2-furyl)phosphine with triosmium clusters: C–H and P–C activation to afford furyne and phosphinidene ligands

Addition of tri(2-furyl)phosphine, PFu3, to [Os3(CO)10(μ-H)2] at room temperature gives [HOs3(CO)10(PFu3)(μ-H)] (1), while in refluxing toluene the same reactants afford [Os3(CO)9{μ3-PFu2(C4H2O)}(μ-H)] (2) resulting from orthometallatation of a furyl ring. Reaction of PFu3 with [Os3(CO)10−n(NCMe)n] (n = 0, 1, 2) affords the substituted clusters [Os3(CO)12−n(PFu3)n] (n = 1–3) (3–5), the phosphine ligands occupying equatorial position in all cases. Heating [Os3(CO)11(PFu3)] (3) in refluxing octane gives [Os3(CO)9(μ3-PFu)(μ3-η2-C4H2O)] (6) which results from both carbon–hydrogen and carbon–phosphorus bond activation and contains both μ3-η2-furyne and furylphosphinidene ligands. All new clusters have been characterized by spectroscopic methods together with single crystal X-ray diffraction for 2, 3 and 6.