共价键稳定性的影响因素

虽然小分子中的共价键强度可以很方便地通过高斯计算而相当准确地得到,一些手册和数据库中也可以直接查出部分键能/离解能数据,但共价键的强弱变化的影响因素分析在化学教学中仍然显得非常重要。共价键的强弱与成键原子及其环境密切相关,其中成键原子因素主要包括原子半径、成键类型、成键轨道类型、相对论效应、电负性、成键数量、反馈效应和孤电子对效应,而成键环境因素包括键间张力效应、离域效应、次级化学键效应、诱导效应和位阻效应。在教学中,我们可以通过对化学键影响因素的分析帮助学生理解共价键键能的变化规律。本文分析了影响共价键强弱的主要因素,并介绍了这种分析思路在化学教学中的应用。

Influence Factors to the Stability of Covalent Bond

Although covalent bond energies in small molecules can be obtained by DFT calculations, or available in some databases and handbooks, analyzing the influence factors of covalent bond is still very important in chemistry teaching. By this analysis, we can guide students to realize the variation tendency of the covalent bond energies. The main influence factors to the covalent bond strength are discussed in this paper and the application of this analyzing approach in chemistry teaching are introduced.