【作者】 方国勇； 胡新根； 徐丽娜； 李新华； 方盈盈；

【Author】 Guo-Yong Fang, Xin-Gen Hu, Li-Na Xu, Xin-Hua Li, Ying-Ying Fang School of Chemistry and Materials Science, Wenzhou University,WenZhou 325035

【机构】 温州大学化学与材料科学学院；

【摘要】 <正>Four fully optimized geometries of uracil-water complexes have been obtained with density function theory (DFT) method at the B3LYP/6-311++G** level. The intermolecular interaction energy is calculated with zero point energy (ZPE) correction and basis set superposition error (BSSE) correction. The greatest corrected intermolecular interaction of the uracil-water complexes is -31.503KJ/mol. Natural bond orbital (NBO) analysis is performed to reveal the origin of the interaction. The strong hydrogen bonds contribute to the interaction energies dominantly. Frequency calculations are carried out on each optimized structure, and their IR spectra are discussed. Vibrational analysis show that there are large red-shifts for H-X (X=O, N and C) stretching vibrational frequencies in the uracil and water complexes. The changes of thermodynamic properties from the monomer to complexes with the temperature ranging from 200K to 800K have been obtained using the statistical thermodynamic method. It is found that four uracil-water complexes can be produced spontaneously from uracil and H,O at lower temperature.更多还原

【Abstract】 Four fully optimized geometries of uracil-water complexes have been obtained with density function theory (DFT) method at the B3LYP/6-311++G** level. The intermolecular interaction energy is calculated with zero point energy (ZPE) correction and basis set superposition error (BSSE) correction. The greatest corrected intermolecular interaction of the uracil-water complexes is -31.503KJ/mol. Natural bond orbital (NBO) analysis is performed to reveal the origin of the interaction. The strong hydrogen bonds contribute to the interaction energies dominantly. Frequency calculations are carried out on each optimized structure, and their IR spectra are discussed. Vibrational analysis show that there are large red-shifts for H-X (X=O, N and C) stretching vibrational frequencies in the uracil and water complexes. The changes of thermodynamic properties from the monomer to complexes with the temperature ranging from 200K to 800K have been obtained using the statistical thermodynamic method. It is found that four uracil-water complexes can be produced spontaneously from uracil and H,O at lower temperature.更多还原