Theoretical study on structure and properties of ANTA and its derivatives

Density functional theory (DFT) calculations were performed for six ANTA derivatives. B3LYP and B3P86 functionals with 6-31+G^** basis set were used. Vibrational analysis showed that the optimized structures have no imaginary frequencies. Heats of formation (HOFs) for the title compounds at 298 K in gas phase were also determined both at two levels using isodesmic work reactions. A good liner equation: Δ_fH^θ(B3P86) =-40.978 98 + 0.984 65×Δ_fH^θ(B3LYP) was obtained from the calculated accurate values between the two levels. It indicates that the designed isodesmic work reactions and calculation accuracy are reliable and feasible. Thermal stabilities were evaluated via bond dissociation energies (BDEs) of the weakest C-NO₂ and the biggest Mulliken charges of nitro group in the title compounds, and two liner equations were extrapolated: BDE_C-NO2=273.022 54-52.210 49×(q_NO2). The relative stability of the title compounds was illustrated according to the results calculated by HOFs, C-NO₂ bond dissociation energy (BDEs) and Mulliken charge of nitro group (q_NO2). The obtained results provided basic data and regularity for the molecular design of new type of high energetic density materials.