Using Trityl Carbocations to Introduce Mechanistic Thinking to German High School Students

Abstract

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.