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

Abstract

Bis(5-amino-1,2,4-triazol-4-ium-3-yl)methane dichloride (BATZM·Cl2 or C5H10N82+·2Cl-) was synthesized and crystallized, and the crystal structure was characterized by single-crystal X-ray diffraction; it belongs to the space group C2/c (monoclinic) with Z = 4. The structure of BATZM·Cl2 can be described as a V-shaped molecule with reasonable chemical geometry and no disorder, and its one-dimensional structure can be described as a rhombic helix. The specific molar heat capacity (Cp,m) of BATZM·Cl2 was determined using the continuous Cp mode of a microcalorimeter and theoretical calculations, and the Cp,m value is 276.18 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·Cl2 are almost equivalent at each temperature. The detonation velocity (D) and detonation pressure (P) of BATZM·Cl2 were estimated using the nitrogen equivalent equation according to the experimental density; BATZM·Cl2 has a higher detonation velocity (7143.60 ± 3.66 m s-1) and detonation pressure (21.49 ± 0.03 GPa) than TNT. The above results for BATZM·Cl2 are compared with those of bis(5-amino-1,2,4-triazol-3-yl)methane (BATZM) and the effect of salt formation on them is discussed.