Combination multi-nitrogen with high heat of formation: theoretical studies on the performance of bridged 1,2,4,5-tetrazine derivatives

A series of bridged tetrazine derivatives (BDDT) were designed by using different bridges to connect two molecules of 1,2,4, 5-tetrazine oxides and then combining different substituents. At the same time, we used DFT-wB97/6–31 + G** method to regularly predict the HOMO–LUMO, heats of formation (HOF), detonation properties, thermal stability, and thermodynamic property orbitals of BDDT compounds. By studying the comprehensive relationship between different substituents and bridging and performance, it is shown that -N(NO₂)₂ and -C(NO₂)₃ are not only excellent groups to improve the heat of formation and detonation properties, but also can cause the compound to have a superior oxygen balance. And that the incorporation of the -N = N- and -NH-N = N- is helpful to enhance their thermal stabilities and HOF. -CH₂-CH₂- and -CH₂-NH- are good for improving the HOMO–LUMO energy gaps. Performances with positive HOF (1170–1590 kJ mol⁻¹), remarkable density (1.88–1.93 g cm⁻³), outstanding detonation properties (D = 9.15–9.80 km s⁻¹, P = 38.24–44.40 GPa), and acceptable impact sensitivity lead C5, D8, E5, E7, F5, and F7 to be the potential candidates of HEDMs.