New green energetic materials based on unsymmetrically substituted pyrazole-tetrazine and hydroperchlorate thereof
Five novel nitrogen-rich energetic materials were synthesized using 3,6-bis(3,5-dimethyl-pyazole-1-yl)-1,2,4,5-tetrazine(BT) and 3,6-bis(pyazole-1-yl)-1,2,4,5-tetrazine as raw materials. The materials were comprehensively characterized by single-crystal X-ray diffraction , FT-IR, mass spectra and elemental analysis. Synthesized compounds showed good experimental densities, ranged from 1.59-1.70 g•cm–3. DSC technology was used for analyzing the thermal stability. Decomposition temperatures of the five energetic materials are ranging from 204.0 to 276.5 °C. Non-isothermal kinetic parameters and formation enthalpy were computed. In addition, friction sensitivity measurements were performed according to BAM methods and the results showed that the five compounds can be classified as insensitive energetic materials. For better understanding of electronic structural characteristics, the electrostatic potential (ESP) and natural bond orbitals (NBO) of compounds 1 and 2 were further computed. The detonation parameters were obtained by the EXPLO5 V6.04. The detonation velocities of the five energetic materials were found to be in the range of 6436 ms-1 to 7759 ms-1 and their detonation pressures are between 15.8 GPa and 24.6 GPa, respectively. Most of them exhibit much better detonation performance than TNT.