4-(1H-tetrazole-5-yl-amino)-1,2,4,5-tetrazin-1-one (TATzO) metal salts: promising pyrotechnic agent

Three 4-(1H-tetrazole-5-yl-amino)-1,2,4,5-tetrazine-1-one (TATzO) metal salts, K₂(TATzO)(H₂O) (1) and Mg(TATzO)(H₂O)₆·2H₂O (2) and Sr(TATzO)(H₂O)₄ (3), were synthesized and characterized using Fourier transform infrared (FTIR), elemental analysis, single-crystal X-ray diffraction, and powder X-ray diffraction patterns. The crystal structure and hydrogen bonding interactions have been analyzed. It turns out that 1 and 3 crystallize into a three-dimensional topological network and have strong π–π stacking and hydrogen bonding interactions. Furthermore, the geometric optimization of 1–3 was performed using B3LYP-D3/def2svp in Gaussian 16 software package and then analyzed by reduced density gradient. The thermal behavior was conducted using differential scanning calorimetry and thermogravimetric (TG). The decomposition temperature of the three complexes exceeds 250 °C, much higher than that of TATzO (230 °C). The thermal decomposition products of 1 were further studied using thermogravimetric-Fourier transform infrared-mass spectrometry (TG/FTIR/MS). The impact sensitivity test indicated that making complexes can help decrease the sensitivity of the original energetic ligand.