摘要
运用密度泛函理论B3LYP方法和6-311+G*基函数对6-甲基-4-羟基嘧啶二聚体进行结构优化与频率计算.结果表明:6-甲基-4-羟基嘧啶二聚体存在两个稳定氢键异构体,均具有C2h对称性.二聚体分子间有强的相互作用,经基组重叠误差BSSE和零点振动能ZPE校正后的相互作用能为-63.285和-70.893 kJ.mol-1.氢键的形成导致H?O(N)伸缩振动频率红移.298.15 K和标准状态下,二聚体形成过程的Gibbs自由能为-16.780和-25.824 kJ.mol-1,显示6-甲基-4-羟基嘧啶二聚体的形成反应是一个热力学自发过程.
Density functional theory B3LYP method and 6-311＋ G^＊ basis set are employed to conduct structure optimiza- tion and frequency calculation of 6-metbyl-4-hydroxy pyrimidine dime. The results indicate that the 6-methyl-4-hydroxy pyrimidine dimer possesses two stable hydrogen bonded isomers with C2h symmetry, and strong interaction is detected between dimer molecules with the interaction energy being -63. 285 and --70. 893kJ·mol^-1 after BSSE and ZPE correction. The formation of hydrogen bonds makes H-O（N） Stretching Vibration Frequencies of dimer red-shifted. At 298.15 K and standard state, the Gibbs free energy for the aggregation from monomer to dimer is -16. 780 and -25. 824kJ·mol^-1 respectively, indicating that the formation reaction of the 6-methyl-4-bydroxy pyrimidine dimer is actually a spontaneous thermodynamical process.
出处
《内江师范学院学报》
2009年第2期30-33,共4页
Journal of Neijiang Normal University
