A DFT treatment on nitro derivatives of pyrazine

In the present work, I carried out a theoretical investigation (density functional theory, DFT) on the structural and energetically properties of pyrazine and its nitro derivatives in the gas phase. All computations were done without any structural symmetry restrictions at 293.15 K and 1 atm. In first step of the calculations, all considered compounds were optimized at B3LYP/6-311G(d,p) level of theory. Then, the vibrational analysis of the molecules was done at the mentioned theoretical method. Also, the natural bond orbital (NBO) population analysis and assignment of the aromaticity properties of the compounds were studied. For good understanding of the structure of compounds, their NMR and IR spectra were considered. The heat of formation (HOF) of the molecules was computed by the isodesmic reaction method. From the bond dissociation energy (BDE) values of the studied materials, all of them are good candidates for high energy density materials (HEDMs).