硝仿肼离子对相互作用的密度泛函理论研究

用密度泛函理论(DFT)方法,在B3LYP/6-31+G^**水平下,求得硝仿肼离子对体系势能面上2种全优化构型.经基组叠加误差(BSSE)和零点能校正,求得离子对最大相互作用能为-420.03kJ/mol,肼和硝仿离子化所需能量可由该值得到完全补偿.离子对间键的主要贡献为库仑作用,但键鞍点上的电子密度值表明共价作用也有显著的贡献.基于统计热力学求得相关体系的热力学性质,298.2K时由自由离子形成最稳定离子对的最大焓变和最大自由能变化分别为-419.72和-376.61kJ/mol

DFT Study of the Intermolecular Interaction of Hydrazinium Nitroformate Ion Pair

Two fully optimized geometries of hydrazinium nitroformate(HNF) ion pairs have been obtained with DFT method at the B3LYP/6-31 G ** level. The binding energies of ion pairs are corrected for the basis set superposition errors(BSSE) and for the zero-point energies(ZPE). The corrected binding energy of the most stable ion pair is predicted to be -420.03 kJ/mol, which can compensate for the total ionization energy needed for the ionization of hydrazine and trinitromethane. The intermolecular bonds between ion pairs primarily consist of Coulomb interaction and, judged by the electron densities at the bond critical points, the covalent interactions also make a remarkable contribution to the bonding. Based on statistical thermodynamics, the thermodynamic properties of the related systems have been calculated. The changes of the enthalpy and Gibbs free energy on going from the ions to the most stable ion pair are predicted to be -419.72 and -376.61 kJ/mol at 298.2 K, respectively.