Integrating Computational Chemistry into an Organic Chemistry Laboratory Curriculum Using WebMO

Given the fundamental importance of computational analysis in organic chemistry, it is incumbent upon instructors to incorporate computational chemistry into any contemporary laboratory course. As a result, educators must decide how best to implement computational chemistry tools and concepts in their courses. We report a suite of introductory exercises has been developed for use in the introductory organic chemistry laboratory at the University of Wisconsin-Madison to train students in the use of computational chemistry to support experimental work throughout the term. By completing these exercises, students become familiar with WebMO as an interface for Gaussian and learn to perform simple geometry optimization, vibrational frequency calculation, NMR chemical shift prediction, molecular orbital (MO), coordinate scan, intrinsic reaction coordinate (IRC), and natural bond orbital (NBO) calculations. These introductory calculations are performed in the context of studying the conformational isomerism of 1,3-butadiene, the impact of electron-withdrawing and electron-donating groups on aromatic pi systems, the prediction of IR and NMR spectra, orbital overlap and geometry changes of a nucleophilic acyl addition reaction, and the fragmentation of radical cations. Most importantly, students learn how to use their computational chemistry results to rationalize experimentally observable chemical phenomena. Thus, the guided exercises provide the foundation upon which students analyze their own computational and experimental data throughout the course.