计算化学在正丁醚制备实验教学中的应用  

Application of Computational Chemistry in the Teaching on the laboratory Experiment of the Preparation of Dibutyl Ether

作　　者：柏一慧[1] 贾似藐 王艺璇 朱钢国[1] 吕新 黄鑫 彭勃[1] BAI Yi-Hui;JIA Si-Miao;WANG Yi-Xuan;ZHU Gang-Guo;LV Xin;HUANG Xin;PENG Bo(College of Chemistry and Life Sciences,Zhejiang Normal University,Jinhua 321004;College of Teacher Education,Zhejiang Normal University,Jinhua 321004)

机构地区：[1]浙江师范大学化学与生命科学学院,浙江金华321004 [2]浙江师范大学教师教育学院,浙江金华321004

出　　处：《化学教育（中英文）》2022年第2期107-113,共7页Chinese Journal of Chemical Education

基　　金：浙江师范大学校一流本科课程(线上线下混合课程)重点项目(2020年)。

摘　　要：正丁醚的制备是重要的大学有机化学实验,为提高学生对该实验所涉及的反应机理和关键操作要点的深入了解,采用Gaussian计算软件对正丁醇在酸催化下和无催化剂下的反应体系进行了研究,重点考察了酸催化下反应的主、副反应方向的反应机理。结果表明无催化剂下,正丁醇在常压液相下几乎不能发生反应;在酸催化下,正丁醇发生取代反应生成醚的反应路径是优势反应通道;酸催化下正丁醇的取代和消除反应速率常数均随温度增加而迅速增大,但消除反应的反应速率随温度增加更快,温度超过420 K消除反应将变得很明显,综合考虑,制备正丁醚的反应温度应控制在130~140℃之间较为合适。利用计算化学以图、表和动图等形式直观、动态、量化地解释了正丁醇成醚和成烯反应的竞争,该结果有助于更好地控制该反应体系,可用作实验教材的补充内容。The preparation of dibutyl ether is an important organic laboratory experiment in college.To help the students fully understand the mechanisms and operational key points involved in this experiment,the reaction systems of 1-butanol under acidic catalysis and without catalyst are studied in this work by using Gaussian software,focusing on the mechanisms of the main and side reactions of the acid-catalyzed system.The results show that without catalyst,the liquid phase reaction of 1-butanol can hardly start at atmospheric pressure.The substitution reaction from 1-butanol to dibutyl ether is the dominant reaction pathway in the acid-catalyzed system.The rate constants of both the acid-catalyzed substitution and elimination of 1-butanol increase rapidly with the increase of the temperature,however,the rate of the elimination reaction for the olefin formation increases faster and the elimination reaction becomes obvious when the temperature exceeds 420 K.A comprehensive consideration suggests that it is appropriate to control the reaction temperature between 130~140℃.The calculation results in this study provide intuitive,dynamic,and quantitative explanations on the competition between the acid-catalyzed ether-forming and olefin-forming reactions of 1-butanol in the form of graphs,tables,and animations.The results are helpful for controlling the reactions and can be used as a supplement for the teaching resources in the course of organic chemistry laboratory.

关 键 词：实验教学 正丁醚的制备 计算化学 机理 反应路径 反应速率 

分 类 号：G642.423[文化科学—高等教育学] TQ223.24-4[文化科学—教育学]