Synthesis and DFT Study of a Diphenylsilanone‐Bridged Dimolybdenum Complex

Reaction of the 30‐electron benzylidyne complex [Mo 2 Cp 2 (μ‐CPh)(μ‐PCy 2 )(μ‐CO)] with excess Ph 2 SiH 2 under visible‐UV irradiation yields the silylene‐bridged complex [Mo 2 Cp 2 (μ‐CPh)(μ‐PCy 2 )(μ‐SiPh 2 )]. This compound undergoes selective oxidation with O 2 to give the unsaturated complex [Mo 2 Cp 2 (μ‐CPh)(μ‐PCy 2 )(μ‐κ 1 :κ 1 ‐OSiPh 2 )], which contains an unprecedented bridging diphenylsilanone ligand, as confirmed by X‐ray diffraction analysis and DFT calculations. The bonding within the central Mo 2 SiO ring of this complex approaches the extreme description of a dimetallacyclosiloxane according to the relevant solid‐state bond lengths and theoretical calculations.