Nitrogen-Atom Exchange Mediated by Nitrido Complexes of Molybdenum

Nitrido complexes N⋮Mo(OC(CF₃)₂Me)₃ (1) and N⋮Mo(OC(CF₃)₃)₃(NCMe) (2) containing fluorinated alkoxide ancillary ligands are synthesized in 57% and 50% yield, respectively. Both complexes undergo N-atom exchange within hours at 30 °C with acetonitrile and benzonitrile in either THF-d₈ or CD₂Cl₂, as shown by ¹⁵N NMR studies using labeled ¹⁵NCMe. In both solvents, 2 is the more active in this process. Additionally, both compounds are substantially more active in THF-d₈ than in CD₂Cl₂. Complex 2 crystallizes in the space group P2(1)/c, adopting a pseudo-square-pyramidal structure in which the nitrido moiety occupies the apical position, 1.633(3) Å away from Mo.