Conversion of a molybdenum nitride to the amide and thence to an oxide and ammonia, reactions involving formal 1,3-prototropic shifts. X-Ray structures of trans-[Mo(NH2)(OH)(dppe)2][OTf]2 and trans-[MoO(OMe)(dppe)2][BPh4](dppe = Ph2PCH2CH2PPh2; OTf = CF3SO3)

Abstract

Protonation of trans-[MoN(N₃)(dppe)₂] by HOTf provides the first example of the conversion of a nitride group to an amide, trans-[Mo(NH₂)(OH)(dppe)₂]²⁺1; this amide is slowly converted to trans-[MoO(OMe)(dppe)₂]⁺2 on stirring in toluene–methanol and ammonia is released; the formation of 1 and 2, whose structures have been authenticated by X-ray crystallography, are explained in terms of formal prototropic shifts: {(H₂O) MoNH}→{HO–Mo–NH₂}→{OMo (NH₃)}