Dehydrogenative Formation and Reactivity of the Unsaturated Benzylidyne-Bridged Complex [Mo₂Cp₂(μ-CPh)(μ-PCy₂)(μ-CO)]: C−C and C−P Coupling Reactions

The title complex is formed through the photochemical treatment of the benzyl complex [Mo2Cp2(μ-CH2Ph)(μ-PCy2)(CO)2] (Cp = η5-C5H5). It reacts reversibly with CO to give the ketenyl complex [Mo2Cp2{μ-C(Ph)CO}(μ-PCy2)(CO)2] and with methyl triflate to give the mixed-carbyne derivative [Mo2Cp2(μ-COMe)(μ-CPh)(μ-PCy2)](CF3SO3), which in turn yields reversibly the C−C coupled products [Mo2Cp2{μ-η2:η2-C(OMe)CPh}(μ-PCy2)L2](CF3SO3) (L = CO, CNtBu) upon addition of L. In the presence of [FeCp2](BF4), the title complex adds three PHEt2 molecules to give the phosphinocarbene derivative [Mo2Cp2{μ-η1:η1,κ1-C(Ph)PEt2}(μ-PEt2)(CO)(PHEt2)](BF4).