Nitrogen-rich salts of 1-aminotetrazol-5-one: Oxygen-containing insensitive energetic materials with high thermal stability

1-Aminotetrazol-5-one (ATO) is a new insensitive nitrogen-rich energetic compound with quite attractive detonation properties (D = 8.88 km s^-1, P = 35.0 GPa), but its formation always requires harsh conditions to facilitate the process. In this contribution we presented an improved synthesis route of ATO in excellent yields and high purity. A large variety of nitrogen-rich salts of ATO were synthesized by means of Bronsted acid-base or metathesis reactions, and confirmed by single-crystal X-ray diffraction for the first time. These compounds were fully characterized by FT-IR and multinuclear NMR spectroscopy, elemental analysis (EA) and differential scanning calorimetry (DSC). All the salts except 7a decompose at temperatures over 220°C; in particular, the aminoguanidinium salt and 3,4-diamino-1,2,4-triazolium salt are fairly stable with a decomposition temperature of 259°C and 261.5°C, respectively. Based on heats of formation calculated with Gaussian 09 and combined with experimentally determined densities, detonation properties of the energetic salts were obtained. They exhibit good thermal stability, excellent impact sensitivities (>40 J), reasonable detonation pressures (23.6-31.0 GPa) and velocities (7.53-8.72 km s^-1) and might be potentially insensitive energetic materials.