碘催化下氯苯的氯代反应——用理论计算化学方法深度分析一道高考试题

Iodine-Catalyzed Chlorination of Chlorobenzene:Application of Theoretical and Computational Chemistry for the In-Depth Analysis of a College Entrance Exam Question

碘催化下氯苯发生氯代反应的产物比例到底是邻二氯苯还是对二氯苯比较高?本文基于涉及该问题的一道比较有争议的高考试题,借助理论计算化学方法,对碘催化下氯苯的氯代反应的反应机理进行了探讨,对反应过程中邻氯代和对氯代两条反应路径进行了模拟,得到了反应路径中各物种的相对能量;在此基础上,对该高考试题进行了全面的分析,将计算结果与参考文献中提供的相应实验结果进行了对照,并对该试题的合理性进行了探讨,为后续的相关试题命题工作提出了建议。本研究可以为其他碘催化下的氯代反应的研究提供依据、为相关试题的编制提供参考、也可在教学中为使学生更好地理解苯的氯代反应的实质提供更丰富的教学资源。

Which of the processes affords a higher yield in the chlorination of chlorobenzene under iodine catalysis,o-chlorination or p-chlorination?Based on a college entrance exam question involving this topic,the reaction mechanism of the chlorination of chlorobenzene catalyzed by iodine is discussed in this paper using computational chemistry.Further,the reaction processes of o-chlorination and p-chlorination are simulated,and the relative energy of each species in the reaction paths is obtained.Thus,a comprehensive analysis of the examination question is carried out,and the calculated results are compared with the corresponding reference experimental results.Additionally,the rationale of the examination question is discussed,and some suggestions are put forth for future related examination questions.This study serves as a support for studies on other iodine-catalyzed chlorination reactions,serves a reference for preparing related examination questions,and provides teaching resources for students to better understand the mechanism of the chlorination of benzene.