Intermolecular Interactions of 3, 6-Bis-nitroguanyl-S-tetrazine Dimers: A Density Functional Theoretical Calculation

Abstract

Nine fully optimized geometries and electronic structures on potential energy surface of 3, 6-bis-nitroguanyl-S-tetrazine (DNGTz) dimers have been obtained with density functional theoretical (DFT) method at the B3LYP/6-31G* level. The intermolecular interaction energy was calculated with zero point energy (ZPE) correction and basis set superposition error (BSSE) correction. The greatest corrected intermolecular interaction energy of the dimers is-62.24 kJ/mol. Natural bond orbital (NBO) analysis is performed to reveal the origin of the interaction. Based on the vibrational analysis, the changes of thermodynamic properties from the monomer to dimer with the temperature ranging from 200.0 K to 800.0 K have been obtained using the statistical thermodynamic method. It was found that the dimerization are mainly contributed by the strong hydrogen bonds, while the binding energies are not only determined by hydrogen bonding. The dimerization process of dimers Ⅰ, Ⅲ, Ⅳ, Ⅴ and Ⅷ can spontaneously occur at 200K, which indicates that these dimers can be stably present at room temperature.