Effect of nitro and amino substituents on structural and energetically properties of 1,2,4,5- tetrazine: DFT and ab-initio study

In the present work, a series of nitrogen-rich compounds based on sym-tetrazine was designed and optimized to obtain molecular geometries and electronic structures at ab initio and density functional theory (DFT, B3LYP) at the levels of 6-31G(d,p), 6-31+G(d,p), 6-311G(d,p), 6-311+G(d,p) and cc-pvDZ. Some important properties such as bond dissociation enthalpy, density, frontier orbital energy, thermodynamic parameters, and heat of formation (HOF) and detonation parameters were then calculated. The volumes of the structures computed to get the densities of the molecules. The HOFs were estimated via isodesmic reactions. It deduced that the introduction of nitro group can improve the detonation properties of the structures. The simulation results revealed that these compounds exhibit excellent performance; and the all structures are viable candidate of high energy density materials (HEDMs). Comparing the detonation properties of molecules with standards (RDX and HMX) shows 3-nitro-1,2,4,5-tetrazine can be an explosive. It has low aromaticity and is unstable.