Formation and Dynamic Properties of the Triangular Rhodium μ3-Sulfido Complex [Rh3Cp*3(μ3-η2-||-C2H2)(μ3-S)]2+(Cp* = η5-C5Me5), Including an Acetylene Ligand Generated by the Coupling and Deprotonation of Two Bridging Methylene Units in a Dirhodium Complex

Deprotonation of the double-bridging μ2-CH2 complex [Rh2Cp*2(μ2-CH2)2(μ2-SH)](BPh4) (Cp* = η5-C5Me5) with [Rh2Cp*2(μ2-OH)3](BPh4) led to the isolation of the trirhodium μ3-S complex [Rh3Cp*3(μ3-η2-||-C2H2)(μ3-S)](BPh4)2, including an acetylene ligand generated by a unique C−C bond coupling and deprotonation of two μ2-CH2 groups. The dynamic property of the acetylene complex in both solution and the solid state was studied by variable-temperature 1H, 13C, and CP/MAS 13C NMR spectroscopy.