An Aluminum-Stabilized Aminonitrene

Aminonitrenes (1,1-diazenes) are central intermediates in nitrogen chemistry and organic synthesis. However, their high reactivity has limited investigations to transient observations, with only a few transition metal-stabilized variants reported to date. Here we report the first isolable main group metal-stabilized aminonitrene, enabled by a novel NNN ligand scaffold. Steric shielding and weak dative interactions between the terminal nitrogen and two aluminum centers allow room-temperature isolation. Optical spectroscopy and quantum-chemical analysis elucidate the electronic structure of this deep blue chromophore, confirming its singlet ground state. In-crystallo photolysis of the azide precursor uncovers an unprecedented pathway involving the formation of N-N bonds to a highly distorted hydrazido intermediate. The findings exemplify an unconventional formation and taming strategy for reactive intermediates through ligand noninnocence and Lewis acid cooperation, opening new avenues for reactive nitrogen chemistry.