1. The neutral compound HN: having univalent nitrogen, and its derivatives RN:. Aminylenes is a recognised but less widely used synonym. RNRI Rule RC-81.1.3.1. NOC Rule C-81.2. Other names that have been used include aminediyls, imidogens, azenes. They may exist in either a singlet or a triplet electronic state (four spin-paired electrons, or two spin-paired and two with parallel spins, respectively). Cf. carbenes. E.g. CH3N: methylnitrene.
2. Until the 1960s, nitrenes had a totally different meaning: analogues of nitrones in which the double-bonded oxygen is replaced by double-bonded carbon, thus azomethine ylides.
