Preparation, crystal and properties of nitrogen-rich energetic salt of bis(Semicarbazide)5,5′-bitetrazole-1,1′-diolate

A novel energetic salt of Bis(semicarbazide) 5′5′-bitetrazole-1′1′-diolate [2(SCZ)∙BTO] was synthesized by using semicarbazide hydrochloride and 1H′1′H-5′5′-bitetrazole-1′1′-diol (BTO) as raw materials, and its structure was characterized by elemental analysis, Fourier Transform infrared spectroscopy (FT-IR) spectroscopy,¹³C NMR spectrum and mass spectrum. The single crystal of the title salt was obtained and its structure was determined by an X-ray single-crystal diffractometer. Results show that 2(SCZ)∙BTO belongs to the monoclinic space group P2₁/c with a density of 1.685 g∙cm^-3. The thermal decomposition behavior was investigated by differential scanning calorimetry (DSC) and thermogravimetry-derivative thermogravimetry (TG-DTG) analyses, and non-isothermal kinetic parameters were also calculated. The results indicated that it has a good thermal stability with a decomposition temperature above 200 °C. The apparent activation energies were 231.2 kJ∙mol^-1 (Kissingerʹs method) and 228.1 kJ∙mol⁻¹ (Ozawa-Doyleʹs method), respectively, and the critical temperature of thermal explosion is 240.6 °C. The enthalpy of formation for the salt was calculated as 158.1 kJ∙mol⁻¹. The detonation pressure (P) and detonation velocities (D) of the salt were determined by using the Kamlet-Jacobs equation. The results indicated that the title salt has potential applications in the field of energetic materials.