Mild N–O Bond Cleavage Reactions of a Pyramidalized Nitrosyl Ligand Bridging a Dimolybdenum Center

Complex [Mo2Cp2(μ-PCy2)­(μ-NO)­(NO)2] (1) was prepared by reacting [Mo2Cp2(μ-H)­(μ-PCy2)­(CO)4] with 2 equiv of [NO]­BF4 and then treating the resulting product [Mo2Cp2(μ-PCy2)­(CO)2(NO)2]­(BF4) with NaNO2 at 323 K, and it was shown to display a bridging nitrosyl ligand with significant pyramidalization at the N atom, a circumstance related to an unusual behavior concerning degradation of the bridging nitrosyl. Indeed, complex 1 reacts with HBF4·OEt2 to give the nitroxyl-bridged derivative [Mo2Cp2(μ-PCy2)­(μ-κ1:η2-HNO)­(NO)2]­(BF4), is reduced by Zn­(Hg) in the presence of trace H2O to give the amido complex [Mo2Cp2(μ-PCy2)­(μ-NH2)­(NO)2], and reacts with excess P­(OPh)3 to give the phosphoraniminato-bridged derivative [Mo2Cp2(μ-PCy2)­{μ-NP­(OPh)3}­(NO)2].