文章基本信息

标题：Using Trityl Carbocations to Introduce Mechanistic Thinking to German High School Students
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作者：Catharina Schmitt ; Michael Schween
期刊名称：World Journal of Chemical Education
印刷版ISSN：2375-1665
电子版ISSN：2375-1657
出版年度：2018
卷号：6
期号：1
页码：18-23
DOI：10.12691/wjce-6-1-4
出版社：Science and Education Publishing
摘要：Mechanistic problem-solving is the scientific core competence of organic chemistry. Hence, many students struggle with developing multivariate mechanistic thinking. They very often rely on memorized rules and propose products without providing a detailed mechanistic pathway. They simply apply problem-solving strategies from general chemistry, which is more product-oriented than organic chemistry. A process-oriented view that is highly demanded in organic chemistry requires the understanding and connection of basic principles and concepts. In order to practice the process-oriented approach and introduce advanced German high school students to mechanistic thinking, we developed a set of three new experiments to generate carbocations in model reactions for the observation of reactive intermediates. Trityl cations proved to be the best ones for an experimental investigation of a reaction’s progress which is accessible with a simple analysis that generates explicit results by changes in color and electric conductivity. The experiments are arranged in a guided inquiry workshop of six steps alternating theoretical (oral group discussions) and experimental phases.
关键词：high school; First-Year Undergraduate; Laboratory Instruction; organic chemistry; problem-solving; carbocations; conductivity; kinetics; Mechanisms of Reactions; reactive intermediates