DNGTz二聚体分子间相互作用的密度泛函理论计算

在DFT-B3LYP/6-31G*水平下,求得3,6二硝基胍基-1,2,4,5-四嗪(DNGTz)二聚体势能面上9种优化几何构型和电子结构.用基组叠加误差(BSSE)和零点能(ZPE)校正,计算了分子间相互作用能,二聚体分子间最大相互作用能为-62.24 kJ/mol.由自然键轨道(NBO)分析揭示了分子间相互作用的本质.对优化构型进行振动分析,并基于统计热力学求得温度200.0～800.0K从单体形成二聚体的热力学性质变化.结果表明,二聚主要由强氢键所贡献,而结合能不仅取决于氢键.二聚体Ⅰ、Ⅲ、Ⅳ、Ⅴ和Ⅶ的二聚过程在200.0K均能自发进行,表明二聚体Ⅰ、Ⅲ 、Ⅳ、Ⅴ和Ⅶ在室温可以稳定存在.

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

Nine fully optimized geometries and electronic structures on potential energy surface of 3,6-bis-nitrogua nyl-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 Ⅶ can spontaneously occur at 200K,which indicates that these dimers can be stably present at room temperature.