Novel catenated N₆ energetic compounds based on substituted 1,2,4-triazoles: synthesis, structures and properties

1-Amino-3,5-dinitro-1,2,4-triazole (ADNT) was prepared using an efficient N-amination process. Three novel catenated N₆ energetic derivatives of ADNT, which contain 1,1'-azobis(3,5-dinitro-1,2,4-triazole) (ABDNT), 1,1'-azobis(3-chloro-5-nitro-1,2,4-triazole) (ABCNT) and 1,1'-azobis(3,5-diazido-1,2,4-triazole) (ABDAT), were synthesized from N-amino oxidative-coupling reactions of ADNT. All compounds were fully characterized by ¹H and ¹³C nuclear magnetic resonance spectroscopies, infrared spectroscopy, elemental analysis, mass spectrum, as well as differential scanning calorimetry (DSC). The crystal structure of compound ABCNT was confirmed by single-crystal X-ray diffraction showing an extensive conjugated structure. The densities of energetic derivatives ranged from 1.71 to 1.93 g cm^-3, and all compounds have positive heats of formation in the range of 774.8 to 2150.8 kJ mol^-1. Based on the measured densities and calculated heats of formation, theoretical performance calculations, including detonation pressures (29.6-42.4 GPa) and detonation velocities (8.22-9.49 km s^-1) were carried out using the Gaussian 09 program and Kamlet-Jacobs equations, and they compared favorably with those of TNT and RDX. These properties make them potentially competitive as new high energy-density compounds.