Amphoteric feature of 3,5-diamino-6-hydroxy-2-oxide-4-nitropyrimidone and its highly-stable energetic anionic salts

Most energetic molecules can only form cations or anions, limiting the structural diversity and performance regulation. In this study, we have presented the interesting amphoteric feature of 3,5-diamino-6-hydroxy-2-oxide-4-nitropyrimidone (DHON), which can be transformed into both DHON⁻ anion and DHON⁺ cation. The structures of the amphoteric salts were characterized by using single-crystal x-ray diffraction, and their energy (density, heat of formation, detonation velocity, and detonation pressure) and stability (thermal decomposition temperature, impact sensitivity, and friction sensitivity) were also carefully studied. Results indicate DHON⁻ anionic salts exhibit very promising stabilities, much superior to DHON⁺ cationic salts. Especially, the hydroxylaminium salt exhibits an extremely high thermal decomposition temperature of 309 °C. The x-ray data and quantum calculations show that the DHON⁻ anion has stronger conjugation and H-bonds than the DHON⁺ cation, thus leading to the higher stability.