A photogenerated triplet aura-nitrene for gold-mediated nitrene transfer.

The isolation and characterization of metal-stabilized, low-valent nitrogen species remain central challenges in advancing nitrogen-atom transfer chemistry. Although gold has emerged as a powerful catalyst in C-N bond formation, proposed mechanisms have consistently bypassed gold nitrenes as key intermediates-leaving their chemistry largely uncharted. Here we report the characterization of a bona fide aura-nitrene, formed via photochemical N2 extrusion from a gold(III) azide complex. In crystallo and solid-state analyses reveal a diverse reactivity landscape, including a nitrene-to-nitro transformation via O2 activation, intra- and intermolecular C-H bond activation, CO fixation and alkyne addition/sigmatropic rearrangement. Computational investigations confirm a triplet ground state, with the nitrene best described as a nitrogen-centred diradical σ-bonded to a formal gold(III) centre. These findings highlight the dual electrophilic and diradical character of gold(III) metallonitrenes and establish a conceptual framework for gold-mediated nitrogen-atom transfer beyond conventional mechanistic paradigms.