Crystal structure, thermal properties and detonation characterization of bis(5-amino-1,2,4-triazol-4-ium-3-yl)methane dinitrate.

Abstract

Bis(5-amino-1,2,4-triazol-4-ium-3-yl)methane dinitrate, BATZM·(NO3)2 or C5H10N82+·2NO3-, was synthesized and its crystal structure determined by single-crystal X-ray diffraction. It crystallizes in the space group Pbcn (orthorhombic) with Z = 4. BATZM·(NO3)2 is a V-shaped molecule where hydrogen bonds form a two-dimensional corrugated sheet with reasonable chemical geometry and no disorder. The specific molar heat capacity (Cp,m) of BATZM·(NO3)2 was determined using the continuous Cp mode of a microcalorimeter and theoretical calculations, and the Cp,m value is 366.14 J K-1 mol-1 at 298.15 K. The relative deviations between the theoretical and experimental values of Cp,m, HT - H298.15K and ST - S298.15K of BATZM·(NO3)2 are almost equivalent at each temperature. The detonation velocity (D) and detonation pressure (P) were estimated using the nitrogen equivalent equation according to the experimental density; BATZM·(NO3)2 has a higher detonation velocity (7927.47 ± 3.63 m s-1) and detonation pressure (27.50 ± 0.03 GPa) than 2,4,6-trinitrotoluene (TNT). The above results for BATZM·(NO3)2 are compared with those of bis(5-amino-1,2,4-triazol-3-yl)methane (BATZM) and bis(5-amino-1,2,4-triazol-4-ium-3-yl)methane dihydrochloride (BATZM·Cl2), and the effect of nitrate formation is discussed.