New energetic salts based on nitrogen-containing heterocycles

New energetic salts (4-9, 11, 13, 16, 21, 22, 29-34, 36, 37, 42, 43, 46, 47) were synthesized via the quaternization of azido or nitro derivatives of imidazole, 1,2,4-triazole, and substituted derivatives of tetrazole with nitric or perchloric acid or with iodomethane followed by metathesis reaction with silver nitrate or silver perchlorate. The structures of 1,4-dimethyl-3-azido-1,2,4-triazolium nitrate (5), 3-azido-1,2,4-triazolium nitrate (6), 1-methyl-4-amino-1,2,4-triazolium perchlorate (16), and 1,4-dimethyl-2-H-1,2,4-triazolium triiodide (20) were confirmed by single-crystal X-ray analysis. Most of the salts exhibit good thermal stabilities and low melting points. By using constant volume combustion energies that were determined experimentally using an oxygen bomb calorimeter, the standard molar enthalpies of formation were derived based on designed Hess thermochemical cycles.