Synthesis and thermal decomposition performance of 3,6,7-triamino-7H-s-triazolo[5,1-c]-s-triazole

3,6,7-Triamino-7H-s-triazolo[5,1-c]-s-triazole was synthesized from triaminoguanidine hydrochloride and cyanogen bromide, and has been prepared at the 30-g scale. A single crystal of 3,6,7-triamino-7H-s-triazolo[5,1-c]-s-triazole was cultivated, and its crystalline density at 293 K was 1.726 g cm⁻³. Its heat of formation (ΔH_f,solid = 470.5 kJ mol⁻¹) was computed by using the density functional theory (DFT) method, and its detonation pressure and detonation velocity were further predicted by EXPLO5 code (D = 9483 m s⁻¹, P = 30.4 GPa). The intermolecular interaction of the title compound was investigated by Hirshfeld surface analysis. Moreover, its thermodynamic performance was evaluated by non-isothermal kinetic methods based on the results of the differential scanning calorimeter (DSC), which shows that the apparent activation energy (E_a) obtained by Kissinger, Ozawa and Starink methods is 223.55, 221.61 and 223.73 kJ mol⁻¹, respectively. Meanwhile, the transformation of molecular structure was analyzed by the rapid scanning Fourier transform infrared spectroscopy (RSFT-IR) under the temperature range from 50 to 300 °C. The reaction pathway was further supported by quantum chemical calculations. 3,6,7-Triamino-7H-s-triazolo[5,1-c]-s-triazole processes good vacuum thermal stability, high detonation performance and low sensitivity. It is convincible that these physical–chemical properties make 3,6,7-triamino-7H-s-triazolo[5,1-c]-s-triazole a promising candidate worthy of further investigation.