大学化学 >> 2022, Vol. 37 >> Issue (6): 2107112.doi: 10.3866/PKU.DXHX202107112

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探讨价层电子对互斥理论的电子对数计算简易方法与应用

张卫(), 马荔, 谢少艾, 汪羽翎, 陈虹锦   

  • 收稿日期:2021-07-31 录用日期:2021-09-10 发布日期:2021-11-04
  • 通讯作者: 张卫 E-mail:weizhang@sjtu.edu.cn
  • 作者简介:张卫, Email: weizhang@sjtu.edu.cn

The Simplified Method for Calculating the Number of Valence Shell Electron Pairs and Application of the VSEPR Theory

Wei Zhang(), Li Ma, Shaoai Xie, Yuling Wang, Hongjin Chen   

  • Received:2021-07-31 Accepted:2021-09-10 Published:2021-11-04
  • Contact: Wei Zhang E-mail:weizhang@sjtu.edu.cn

摘要:

针对价层电子对互斥理论中关于卤素、氧族等p区非金属元素作为配位原子提供电子数为1、0等未做明确说明的问题,通过数学公式推导解释了数字背后的意义,完善了将中心原子和配位原子按不同计算规则、更简便地计算价层电子对数的方法。应用推导出的简便价层电子对计算规则探讨了一种判断链状结构有机小分子的杂化类型的新方法,并讨论了长周期p区非金属元素的最外层s电子的钻穿作用对价层电子总数的影响以及利用电负性差异比较共价型分子键角大小时需要考虑多重键的影响等,对VSEPR法的应用做了有益补充。

关键词: 价层电子对互斥理论, 价层电子对数, 杂化类型, 键角

Abstract:

Aiming at the unspecified problem that the number of electrons provided by a halogen, oxygen group, and other p-group non-metallic elements as coordination atoms is 1, 0 etc. in VSEPR theory, this article focuses on explaining the numbers using mathematical formula and presents a simplified method for calculating the valence electron pairs using calculation rules for the central and coordination atoms. This article specifically presents a new method to analyze the hybrid type of organic small molecules with a chain structure using the deducted calculation rules. Furthermore, it discusses how the outermost s-electrons of the long-period p-group non-metallic elements impact the total number of valence electrons via the penetration effect and the mutual influence of multiple bonds to compare the bond angles of covalent molecules using the differences in the electronegativity. This method is expected to be a useful supplement to the application of VSEPR theory.

Key words: VSEPR, Valence electron pairs, Hybrid type, Bond angle

MSC2000: 

  • G64