Reactivity of [1],[1]Disilamolybdenocenophane toward Zerovalent Platinum Complexes

The results of studies of the reactivity of strained [1],[1]disilamolybdenocenophane toward zerovalent platinum complexes are reported. Whereas [Pt(PEt₃)₃] underwent clean insertion into both Si−C_ispo bonds of the twofold-bridged molybdenocene, the reaction with the tricyclohexylphosphine analogue is considerably more complex. Thus, treatment of the molybdenum compound with 2 equiv of [Pt(PCy₃)₂] results in a trinuclear cluster. To gain insight into the mechanistic aspects, the reaction was performed in a 1:1 stoichiometry. Multinuclear NMR spectroscopy revealed the presence of different species in solution. Two constitutional isomers were identified by X-ray diffraction analyses, one presumably depicting an intermediate in the formation of the trinuclear cluster. The predominant isomer in solution was identified as the product of C−H oxidative addition to the platinum phosphine fragment. Its solid-state structure displays an unusual coordination mode of platinum, and structural parameters suggest the formulation as the σ-complex of a Mo−Si bond.