物理化学学报 >> 1989, Vol. 5 >> Issue (04): 438-445.doi: 10.3866/PKU.WHXB19890412

研究论文 上一篇    下一篇

氢氰酸、异氰酸与水氢键的量子化学研究

王曙光; 潘道皑; 袁身刚   

  1. 华东师范大学化学系; 上海有机化学研究所
  • 收稿日期:1988-08-08 修回日期:1988-10-24 发布日期:1989-08-15
  • 通讯作者: 王曙光

QUANTUM CHEMISTRY STUDIES OF HYDROGENBONDED DIMERS OF HCN, HNC AND H2O

Wang Shuguang*; Pan Daokai; Yuan Shengang   

  1. Department of Chemistry; East China Normal University; Shanghai Institute of Organic Chemistry; Academia Sinica
  • Received:1988-08-08 Revised:1988-10-24 Published:1989-08-15
  • Contact: Wang Shuguang

摘要: 用LCAO-MO-SCF的ab initio方法, 在4-31G水平上, 对CNH…OH_2, NCH…OH_2, HNC…HOH, HCN…HOH四种氢键体系进行了能量梯度法的构型优化和计算, 并分别进行了Morokuma能量分解分析, 计算了各作用能对氢键形成的贡献。考察了各作用能随氢键键长的变化情况。从理论上解释了各氢键体系键能强弱次序的变化。在一般情况下,静电作用的大小可以决定氢键键能的强弱次序; 但在某些情况下, 电荷迁移作用也很重要, 需从这两方面综合考虑才能确定键能的强弱次序。

Abstract: The four Hydrogen-Bonded systems of C≡N—H…OH_2, N≡C—H…OH_2 and H—N≡C…H—OH,H—C≡N…H—OH have been studied with ab initio LCAO-MO-SCF methods at 4-31G level. The complete structure optimization have been carride out. We have also performed the Morokuma's Energy Decomposition Analysis for these four systems.The results show that, the electrostatic interaction (ES) is the most important attractive component in the H-Bond and the charge transfer interaction (CT) is the next largest attractive one. In most cases the order of ES can determine the H-Bond strength order betreen similar systems such as C≡N…H—OH_2 N≡C_2. But in some particular cases, we must consider both ES and CT to predict the order of H-Bond strength, such as H—N≡C…H—OH and H—C≡N…H—OH. We have discussed that the energy components are strongly distance dependent. At relatively small separations, the ES, CT, PL can all be important attractive components. At longer distance for the same systems the relative importance of the CT interaction maybe increased.