Quantifying the Product Distribution of a Chemical Reaction by 1H NMR Spectroscopy: A Cooperative Learning Approach for the Undergraduate Organic Chemistry Laboratory

• Published in: Journal of chemical education 2017-09, Vol.94 (9), p.1383-1387
• Main Authors: Yennie, Craig J, Hopson, Russell, Hess, Kathleen M
• Format: Article
• Language: English
• ISSN: 0021-9584; 1938-1328
• DOI: 10.1021/acs.jchemed.6b00601

This enhancement of a classic laboratory experiment investigates the kinetic and thermodynamic control of a reaction utilizing 1H NMR spectroscopy instead of melting point analysis to determine the product distribution. In this experiment, semicarbazide is reacted with cyclohexanone and 2-furaldehyde under varying buffer and temperature conditions to yield semicarbazone derivative products. After 1H NMR analysis of the products, students compile the class data in a cooperative setting facilitated by graduate teaching assistants. As a result, students are able to analyze a larger data set in this cooperative learning environment in order to describe the product distribution of the reaction on the basis of trends as opposed to using a single data set. The application of 1H NMR spectroscopy to determine the product distribution of the reaction introduces a modern approach to study a well-established example of the kinetic and thermodynamic control of a reaction.