休克尔分子轨道法处理C_(n)H_(n)(n=4和8)体系的π键键级的释疑  

Elucidation on the Treatment of π Bond Order of C_(n)H_(n)(n=4 and 8)Systems Using Hückel Molecular Orbital Method

作　　者：王慧婷 石小飞 魏东辉[1] Huiting Wang;Xiaofei Shi;Donghui Wei(College of Chemistry,Zhengzhou University,Zhengzhou 450001,China)

机构地区：[1]郑州大学化学学院,郑州450001

出　　处：《大学化学》2023年第2期266-270,共5页University Chemistry

基　　金：国家自然科学基金面上项目(21773214);河南省自然科学基金优秀青年科学基金项目(212300410083);河南省高等学校青年骨干教师培养计划(2020GGJS016)。

摘　　要：休克尔分子轨道(HMO)法对C_(4)H_(4)和C_(8)H_(8)单环多烯体系进行处理时会将其默认为共轭离域的三重态分子,这与其真实分子的单重态结构不符。运用密度泛函理论(DFT)分别对其单重态和三重态进行结构优化,并计算出更为精确的四元环、八元环的π键键级。基于DFT计算结果,我们提出了解决HMO法计算C_(4)H_(4)和C_(8)H_(8)单环多烯体系的π键键级误差的方案。The C_(4)H_(4) and C_(8)H_(8) monocyclic polyene systems are treated automatically as the conjugated delocalized triplet molecules by Hückel molecular orbital(HMO) method,but this is inconsistent with their actual ground state structures associated with singlet state.In this work,both the singlet and triplet molecular structures of the fourmembered ring and the eight-membered ring were optimized by density functional theory(DFT),and the more accurate π bond orders were calculated.Based on the DFT calculated results,we suggested a solution that can correctly compute the π bond orders in the C_(4)H_(4) and C_(8)H_(8) monocyclic polyene systems by using the HMO method.

关 键 词：HMO方法 密度泛函理论 π键键级 键长 

分 类 号：G64[文化科学—高等教育学] O6[文化科学—教育学]