Density functional theory at B3LYP/aug-cc-pvDZ level is applied to study the geometries, bond dissociation energies and energetic material properties of pentrazine derivatives in which hydrogen atom of pentrazine have been substituted by CN, NO₂, NH₂, N₃, N₂H, NHNH₂, N₄H and N₄H₃ groups. Compared with the parent molecules unsubstituted, derivatives substituted by CN and NH₂ groups result in higher bond dissociation energies, whereas the other lead to lower ones. The studies indicated that the higher heats of formation of compounds of substituent groups possess, the higher ones of derivatives. The normalized heats of formation of these derivatives substituted by N₄H₃, NO₂, H, N₂H, N₄H, N₃ and CN are 72.6～108.9 kJ, which is higher than that of triazido-s-triazine (70.2 kJ) reported. For derivatives substituted by N₄H, N₃, N₄H₃, N₂H and CN groups, heats of formation calculated lie in the range of 871.4～1159.3 kJ•mol^－1, but derivatives substituted by N₄H and N₄H₃ show low dissociation energies and relatively low stabilities. So derivatives substituted by N₃, N₂H and CN groups should be applicable as potential of high nitrogen content high energy materials (HNC-HEMs).

Key words: high nitrogen content high energy material (HNC-HEM), pentrazine, substitutent group containing nitrogen, dissociation energy, heat of formation