C_2H_5N_4^+-C_6H_3N_3O_7^-氢键相互作用的理论研究

Theoretical Study on the Hydrogen Bonding Interaction of C_2H_5N_4^+-C_6H_3N_3O_7^-

运用密度泛函理论方法,在B3LYP/6-311++G**水平上对4-氨基-1,2,4-三唑阳离子(AT)和2,4,6-三硝基苯酚阴离子(PA)形成的氢键二聚体进行理论计算研究.计算得到4种稳定结构的氢键复合物及最稳定异构体D1的振动频率、电子吸收光谱与热力学性质.结果表明,氢键复合物中存在较强的N—H…O与C—H…O红移氢键.经过基组重叠误差和零点振动能校正后,D1的氢键相互作用能为-30.71kJ/mol.热力学计算显示,在298.15K和标准状态下,D1气态氢键复合物分子的形成过程是放热、熵减小的非自发过程,但在低温下能自发进行.D1分子的标准摩尔生成焓和标准摩尔生成自由能分别为98.7,474.4kJ/mol.

The hydrogen bonded dimer between C2H5N＋4 and C6H3N3O-7 was studied,using the density functional theory（DFT） at B3LYP/6-311＋＋G＊＊ level.By calculation,four stable hydrogen bonded complexes and the vibration frequency,electronic absorption spectrum and thermodynamic property of the most stable isomer D1 were obtained.A strong N—H…O and a C—H…O red-shift hydrogen-bonds were shown to exist in the hydrogen bonded complexes.After basis set superposition error（BSSE） calibration and zero-point vibration energy calibration,the hydrogen bonding interaction energy of D1 was-30.71 kJ/mol.The results of thermodynamic calculation showed that the formation of D1 gaseous hydrogen bonded complex molecules was an exothermic,entropy decreasing and non-spontaneous process at 298.15 k,but it could be spontaneous at low temperature.The standard molar formation enthalpy and free energy of D1 were 98.7 kJ/mol and 474.4 kJ/mol at 298.15 k,respectively.