Nitrogen-Rich Salts based on 1,1’-Dihydroxy-5,5’-Azobistetrazole: aNew Family of Energetic Materials with Promising Properties

A series of nitrogen-rich energetic heterocyclic 1,1’-dihydroxy-5,5’-azobistetrazole (AZO) salts are synthesized with ethylenediammonium (1), hydrazinium (2), semicarbazidium (3), guanidinium (4), 1-amino-1,2,3-triazolium (5), 4-amino-1,2,4-triazolium (6) and 5-amino-tetrazolium (7). The salts have characterized through elemental analysis, Fourier Transform infrared spectroscopy (FT-IR) spectroscopy, ¹H NMR, ¹³C NMR and mass spectrometry. The crystal structures determined by single crystal X-ray diffraction. The thermal decomposition behaviors investigated by using the DSC and TG-DTG technologies. The enthalpies of formation are calculated through the combustion heat data measured through the oxygen bomb calorimetry. All the salts have acceptable thermal stability with the highest decomposition temperature of 301.8 °C, excellent high positive formation enthalpies ranging from 350.5 kJ mol⁻¹ to 1500.3 kJ mol⁻¹, and good insensitivity to outer stimuli compared to the traditional RDX. The promising detonation parameters of the salts yield detonation velocities (D) and pressures (P) are ranging from 7327 m s⁻¹ to 8931 m s⁻¹, and from 21.7 GPa to 32.7 GPa. Considering the advantage, it is possible to prepare these nitrogen-rich energetic salts as promising energetic materials. It's hoped that the present author's research contributed to the expansion and application of the chemistry of 1,1’-dihydroxy-5,5’-azobistetrazole.