Alkaline earth metal salts of 3,6-dinitramino-1,2,4,5-tetrazine: Prospective candidates for environmentally friendly energetic applications

[Display omitted] •Four Alkaline earth metal energetic salts were synthesized.•All of these salts possess better thermal stability and lower sensitivities.•All compounds have differently reticular structures.•Thermal analyses, heats of formation, and sensitivities were investigated.•The results show them prospective for potential applications. Four alkaline earth metal salts (Mg2+(1), Ca2+(2), Sr2+(3), Ba2+(4)) of 3,6-dinitramino-1,2,4,5-tetrazine were synthesized and characterized by elemental analysis, IR spectroscopy, and single-crystal X-ray diffraction. Structural analysis revealed that all compounds have differently reticular structures, where each metal is bound in a specific and characteristic fashion. Thermal behaviors investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) show that all of these salts possess better thermal stability compared to neutral 3,6-dinitramino-1,2,4,5-tetrazine, with the thermal decomposition temperatures of 162 °C (1), 262.1 °C (2), 268 °C (3) and 267 °C (4), respectively, due to their plenty of coordinate bonds and intermolecular H-bonds. Besides, the kinetic parameters have been determined by non-isothermal kinetics at various heating rates. All these salts are insensitive to the stimulation of impact and friction (impact sensitivity > 40 J, friction sensitivity > 360 N), which can be considered as potential eco-friendly insensitive energetic compounds.