Molecular face theory being applied to investigate the bond length, polarizability and aromaticity in the heterocyclic compounds

Abstract

本文使用MELD精密从头计算中的CISD/3-21+G(d,p)方法, 计算杂环化合物的单电子所受到的作用势(PAEM)和分子形貌(MF), 探讨这些分子的化学键的单电子势垒( D pb)与各自相应的化学键键长的关系, 得出化学键的单电子势垒可以用来表征化学键的强弱; 探讨这些分子的杂环内的单电子势垒( D pr)与分子极化率的关系, 可知该势垒可以描述分子的变形性; 绘出杂环化合物的分子形貌, 计算垂直于分子平面方向上的边界轮廓界面的电子密度, 探讨该分子界面电子密度的均匀度与杂环化合物芳香性的关系, 进而为杂环芳香化合物的芳香性提出一个定量的标度. Ab initio CISD/3-21+G(d,p) method in MELD package in combination with our own program was used to calculate the potential acting on an electron within a molecule (PAEM) and molecular face (MF). We have investigated the relationship between the single potential barrier ( D pb) of the chemical bonds and their respective bond lengths. It is obtained that the single potential barrier of the chemical bond can be used to characterize the strength of chemical bond. We have explored the correlation between the single potential barrier of the ring ( D pr) and molecular polarizability. It can be shown that the potential barrier can be used to describe the molecular distortion. We have drawn the molecular face of the heterocyclic compounds and calculated the molecular intrinsic characteristic contour and its correspondent electron density. The correlation between the electron density uniformity of molecular boundary and aromaticity of heterocyclic compounds has been studied. Moreover, it can provide us a quantitative scale of describing the aromaticity of heterocyclic compounds.