Synthesis and characterization of the nitrophenol energetic ionic salts of 5,6,7,8-tetrahydrotetrazolo[1,5-b][1,2,4]triazine

Nitrophenol energetic ionic salts based on the 5,6,7,8-tetrahydrotetrazolo[1,5-b][1,2,4]triazine (TZTN, 1) cation and nitrophenol anions have been synthesized in high yields by neutralization reactions. All the salts were characterized by X-ray single-crystal diffraction technology, IR spectroscopy, elemental analysis, and DSC measurements. The heats of formation of 2-4 were calculated by using isodesmic reactions. The calculated detonation pressures of these salts range from 29.7 to 32.6 GPa and their detonation velocities fall between 8337 and 8613 m s^-1; these properties make them competitive energetic materials. In addition, the sensitivities towards impact, friction, and flame were tested, and the results indicated that salts 2 and 3 have acceptable sensitivities, whereas salt 4 shows relatively high sensitivity towards impact and flame.