一种改进的休克尔分子轨道模型预测纯碳环分子稳定结构  

A Modified Hückel Molecular Orbital Model to Predict the Structure of Cyclo[2n]carbons

作　　者：张亦弛 侯华[1] 王宝山[1] Yichi Zhang;Hua Hou;Baoshan Wang(College of Chemistry and Molecular Sciences,Wuhan University,Wuhan 430072,China)

机构地区：[1]武汉大学化学与分子科学学院,武汉430072

出　　处：《大学化学》2022年第1期196-201,共6页University Chemistry

基　　金：武汉大学通识课程教学改革项目。

摘　　要：针对休克尔分子轨道(HMO)理论中只考虑相邻原子轨道相互作用的缺点,提出了一种改进的HMO模型,明确考虑间位碳原子共振积分,采用对称性匹配的分子轨道,得到了π共轭体系的能级公式,发现分子对称性降低可产生额外稳定化能,从而正确解释了纯碳环C2n分子稳定结构中键角交替变化规律,为理解二级Jahn-Teller效应提供了新思路。Hückel Molecular Orbital(HMO) theory is popular in chemistry, but it assumes that the reduced resonance integrals exist only between the nearest-neighbor carbon atoms. Such an approximation has been justified by the explicit inclusion of the resonance integrals between the meta-directing π-bonded atoms. The energy eigenvalues are obtained using the symmetry-adapted molecular orbitals, together with the extra stabilization energy due to symmetry breaking. The polyynic geometries of cyclo[2 n]carbons with alternating angles are explained rationally using the modified HMO model, which gains new insights on the second-order Jahn-Teller effect for carbon rings.

关 键 词：休克尔分子轨道理论 共振积分 纯碳环 对称性 能级 

分 类 号：G64[文化科学—高等教育学] O6[文化科学—教育学]