Divalent nitrogen-rich cationic salts with great gas production capacities

Abstract

Monocyclic nitrogen-rich 3-(aminomethyl)-4,5-diamine-1,2,4-triazole (1) and fused cyclic 3,7-diamine-6-(aminomethyl)-[1,2,4] triazolo [4,3-b] [1,2,4] triazole (9) were synthesized through the convenient cyclization reaction from the readily available reactant. Their energetic salts with high nitrogen content were proved to be rare examples of divalent monocyclic/fused cyclic cationic salts according to the single crystal analyses. The structure of intermediate B was also identified and verified by its trivalent cation crystal 17.5H2O indirectly. Energetic compounds 2–8 and 10–17 were fully characterized by NMR spectroscopy, infrared spectroscopy, differential scanning calorimetry, elemental analysis. These energetic salts exhibit good thermal stability with decomposition temperatures ranged from 182 °C to 245 °C. The sensitivity of compounds 2, 6, 10 and 14 is similar or superior to that of RDX while the others were much more insensitive to mechanical stimulate. Furthermore, detonation velocity of 10 (8843 m/s) surpass that of RDX (D = 8795 m/s). Considering the high gas production volume (≥808 L/kg) of 2, 4, 10 and 12, constant-volume combustion experiments were conduct to evaluate their gas production capacities specifically. These compounds possess much higher maximum gas-production pressures (Pmax: 7.88–10.08 MPa) than the commonly used reagent guanidine nitrate (GN: Pmax = 4.20 MPa), which indicate their strong gas production capacity.