Structural and energetically study on nitro and amino derivatives of 1,2,3,5-tetrazine

Although many tetrazine based compounds have been synthesized and studied theoretically, the chemistry of molecules based on 1,2,3,5-tetrazine are little known. In the present study, the nitro and amino derivatives of 1,2,3,5-tetrazine were designed and investigated to get 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, nucleus-independent chemical shifts (NICSs), and heat of formation and detonation parameters were then calculated. Also, IR and NMR spectra of the structures were simulated. The volumes of the structures computed to get the densities of the molecules. The heats of formations (HOFs) were estimated via isodesmic reactions. All calculations carried out in gas phase at temperature 298 K and pressure 1 atm. 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 4,6-dinitro-1,2,3,5-tetrazine can be an explosive.