Tandem deprotonation/azide-tetrazole tautomerization of 4,6-diazido-N-nitro-1,3,5-triazin-2-amine in dimethylsulfoxide solutions: a theoretical study

4,6-Diazido-N-nitro-1,3,5-triazin-2-amine (2) is a new promising high-energy organic compound that isomerizes in dimethylsulfoxide (DMSO) solutions to form unknown products with interesting C-13 and N-15 NMR spectroscopic characteristics. To identify these products, the relative energies and the C-13 and N-15 chemical shifts were calculated for various prototropic and valence isomers of 2. It was found that this diazide in DMSO solutions exists in equilibrium with the deprotonated form of 5-azido-N-nitrotetrazolo[1,5-a][1,3,5]triazin-7-amine (8). The anion 8 is also observed in DMSO solutions of energetic salts derived from 2 and guanidines or 4H-1,2,4-triazol-4-amines. The tandem transformations of 2 in DMSO solutions found may be of interest from both theoretical and practical points of view, for instance, in the synthesis of new energetic materials, using the reactions of anion 8 with various electrophilic agents.