Photochemistry of a 1,1-diazene, N-(2,2,5,5-tetramethylpyrrolidinyl)nitrene

The photochemistry of the 1,1-diazene has never been examined due to its transient nature. Several theoretical groups have calculated the order of the electronic states of the 1,1-diazene (aminonitrene, N-nitrene) during the past decade. Goddard's GVB-CI calculations of the parent H2N-N suggest a ground-state singlet with low-lying n,π* singlet (50.7 kcal) and triplet states (13.8 kcal) (Figure 1). The 1,1-diazene is isoelectronic with the carbonyl, a functional group whose photochemistry is well documented. The recent synthesis and characterization of persistent 1,1-diazenes allows an investigation of the photochemical reactivity of this species. We report the direct and sensitized irradiation of N-(2,2,5,5-tetramethylpyrrolidinyl)nitrene 1 in the visible region (n,π* transition) which reveal both unimolecular and bimolecular photoreactivity. In addition, the fluorescence spectrum of a 1,1-diazene has been obtained