Reductive Nitrosylation of V2O5 and MoO3 with Hydroxylamine in the Presence of 1,4,7-Triazacyclononane

Abstract

From the reaction mixture of an alkaline aqueous solution of V2O5, 1,4,7-triazacyclononane (tacn) and hydroxylamine, orange, diamagnetic crystals of [V(tacn)(NO)2(NH3)]I were obtained upon addition of NaI. Air-stable [V(tacn)(NO)2(N3)] has also been isolated and characterized by X-ray crystallography. In a similar reaction using MoO3 as starting material, yellow crystals of [MoCl(tacn)(NO)(H2NO)]ClO4 were isolated and characterized by X-ray crystallography. A less reducing reagent, N-methylhydroxylamine, produces in the above reaction mixture colorless crystals of [MoVI(tacn)(O)2(MeNHO)]ClO4; its structure has also been determined. A mechanism for the formation of {M(NO)2}6 complexes (M = Mo, V) from high-valent oxometallates and hydroxylamine is proposed.