Reductive Nitrosylation of V2O5 and MoO3 with Hydroxylamine in the Presence of 1,4,7-Triazacyclononane
From the reaction mixture of an alkaline aqueous solution of V 2 O 5 , 1,4,7-triazacyclononane (tacn) and hydroxylamine, orange, diamagnetic crystals of [V(tacn)(NO) 2 (NH 3 )]I were obtained upon addition of NaI. Air-stable [V(tacn)(NO) 2 (N 3 )] has also been isolated and characterized by X-ray crystallography. In a similar reaction using MoO 3 as starting material, yellow crystals of [MoCl(tacn)(NO)(H 2 NO)]ClO 4 were isolated and characterized by X-ray crystallography. A less reducing reagent, N -methylhydroxylamine, produces in the above reaction mixture colorless crystals of [Mo VI (tacn)(O) 2 (MeNHO)]ClO 4 ; 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.