物理化学学报 >> 1991, Vol. 7 >> Issue (03): 270-275.doi: 10.3866/PKU.WHXB19910303

研究论文 上一篇    下一篇

乙醛二聚体的从头计算

蔡国强; 董南   

  1. 浙江大学化学系,杭州 310027;杭州大学化学系
  • 收稿日期:1990-02-25 修回日期:1990-07-30 发布日期:1991-06-15
  • 通讯作者: 蔡国强

Ab initio Molecular Orbital on the Acetaldehyde Dimer

Cai Guo-Qiang; Dong Nan   

  1. Department of Chemistry, Zhejiang University, Hangzhou 310027; Department of Chemistry, Hangzhou University, Hangzhou
  • Received:1990-02-25 Revised:1990-07-30 Published:1991-06-15
  • Contact: Cai Guo-Qiang

摘要: 用ab initio分子轨道法在STO-3G和6-31G水平上, 全构型优化, 对二聚乙醛的各种稳定构型进行了研究。结果表明, 在STO/6-31G水平上, 最稳定的乙醛二聚体为具有对称中心的环状结构, 包含由醛基氢和醛基氧组成的二个C—H…O氢键。结合能为-20.17 kJ·mol~(-1), 与实验估计的结合能-22.39±0.15 kJ·mol~(-1)比较接近。STO-3G过低估计了乙醛二聚体的结合能, 在不同构型的相对稳定性方面也与6-31G不一致。

关键词: 乙醛二聚体, 从头计算分子轨道法, 构型的稳定性

Abstract: Ab initio molecular orbital calculations were performed on various structures of the acetaldehyde dimer at STO-3G and 6-31G levels. All the fully optimized structures of the dimer are cyclic structures with two C—H…O hydrogen bonds. At 6-31G level, the most stable geometry of the dimer is a symmetric one and the C—H…O hydrogen bonds are composed of hydrogen in—CHO group and carbonyl oxygen. The binding energy is —20.17 kJ·mol~(-1), which is in reasonable agreement with the estimated experimental value of -22.39±0.15 kJ·mol~(-1). The STO-3G basis set underestimates the binding energy and fails to give consistent description of the relative stabilities of various structures of the dimer with the 6-31G basis set.

Key words: Acetaldehyde dimer, Ab initio molecular orbital, Stabllities of structures