Catalyzed autoxidation of azide by cobalt(II) (2,3,9,10-tetramethyl-1,4,8,11-tetraazacyclotetradeca-1,3,8,10-tetraene)2+

The catalytic autoxidation of azide by Co(tim)2+ was studied. In the presence of dioxygen Co(tim)(H2O)2 2+ (tim=2,3,9,10-tetramethyl-1,4,8,11-tetraazacyclotetradeca-1,3,8,10-tetraene) reacts with azide in a complex process to produce Co(tim)(N3)x (3−x)+ (x=1 or 2) (λmax at 340 nm) and dinitrogen. The reaction is clearly catalytic with up to several hundred turnovers. The dioxygen dependence of the reaction implies the involvement of an oxygen adduct, stabilized by an axial azide ligand.