环辛四烯的结构、芳香性及其异构化反应

Structure,Aromaticity,and Isomerization Reactions of Cyclooctetraene

环辛四烯为八个sp2碳原子构成的环状轮烯,对其结构和性能的理解涉及一系列化学基本理论和基本概念的应用。本文通过本科生创新实验指导学生用计算化学方法研究了环辛四烯的电子结构、几何构型、芳香性、异构化反应等内容,以期引导学生达成如下学习目标:1)充分认识结构决定性能、性能反映结构的科学思想;2)了解Hückel分子轨道法(HMO)处理4n型π电子体系的局限性;3)区分芳香性、反芳香性和非芳香性等基本概念,理解判定共轭π电子体系基态(单重态)芳香性的Hückel规则以及激发态(三重态)芳香性的Baird规则;4)明确计算化学方法是理解物质结构和性能的重要手段。

Cyclooctatetraene is a cyclic polyene composed of eight sp2 carbon atoms.Understanding its structure and properties involves the application of various fundamental chemical theories and concepts.This article guides undergraduate students to use computational chemistry methods to investigate the electronic structure,geometric configuration,aromaticity,and isomerization reactions of cyclooctatetraene,with the aim of helping students achieve the following learning objectives:1)understand the scientific concept that structure determines properties and properties respond to structure;2)understand the limitation of the Hückel molecular orbital method(HMO)in dealing with 4n-typeπ-electron systems;3)distinguish fundamental concepts such as aromaticity,antiaromaticity,and non?aromaticity and comprehend the Hückel’s rule for determining the aromaticity of the ground state(singlet state)of a conjugatedπ-electron system,as well as the Baird’s rule for determining the aromaticity of excited states(triplet state);and 4)clearly recognize that computational chemistry methods are essential tools for understanding the structure and properties of materials.