Symmetric cascade of dinitrotriazine and dinitropyrimidine rings on central triazine core: Computational investigation of probable heat-resistant energetic materials

Abstract

Exploring high-nitrogen energetic molecules and their structure-property relationships represents a dynamic and evolving area of research in energetic materials science. In this work, two heat-resistant energetic materials with dinitrotriazine and dinitropyrimidine rings connected to a central triazine core via -NH- linkages were designed. Their physicochemical and energetic properties were investigated by using the density functional theory (B3LYP/6-311G(d,p)). Both designed compounds exhibit a positive heat of formation that surpasses well-known heat-resistant explosives, 2,2’ ,4,4’ ,6,6’-hexanitrostilbene (HNS), 1,3,5-triamino-2,4,6-trinitrobenzene (TATB), 2,6-bis(picrylamino)-3,5-dinitropyridine (PYX), 2,2’,2”,4,4’,4”,6,6’,6”-nonanitroterphenyl (NONA), and 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105), due to the presence of endothermic triazine and pyrimidine rings in their structures. The presented compounds demonstrate detonation performances (D > 7.5 km/s, P > 21.7 GPa) superior to HNS and comparable to those of TATB, PYX, NONA, and 2,4,6-tri(3,5-diamino-4-nitropyrazol-1-yl)-1,3,5-triazine (NPX-02). Electrostatic potential, electron localization function, and different aromaticity indexes were also examined and compared with traditional heat-resistant explosives. Additionally, they possess a high C-NO2 bond strength (>220 kJ/mol), a lower heat of detonation (Q < 1100 cal/g), and a better safety factor (>400), indicating their low sensitivity. These computationally derived physicochemical and energetic properties make them promising candidates for further research and potential application as insensitive and heat-resistant energetic materials; however, additional experimental efforts are required to validate the predicted properties.