Molecular Orbital Analysis of Diels-Alder Reactions: A Computational Experiment For An Advanced Organic Chemistry Course

TCE

The Chemical Educator

ISSN: 1430-4171 (electronic version)

Table of Contents

Abstract Volume 15 (2010) pp 55-58

Molecular Orbital Analysis of Diels-Alder Reactions: A Computational Experiment For An Advanced Organic Chemistry Course

Stanislaw Skonieczny*, Mima G. Staikova and Andrew P. Dicks

Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, Canada, M5S 3H6, sskoniec@chem.utoronto.ca
Received November 30, 2008. Accepted September 9, 2009.

Published: 16 January 2010

Abstract. A computational experiment developed for a senior undergraduate organic chemistry course is described. The experiment utilises the Gaussian 03 suite of programs in tandem with WebMO Pro software. The latter serves as a web-based interface and incorporates molecular construction, visualisation facilities and direct result evaluation. Students research favourable reactant pairs, optimise structures, calculate energies and visualise molecular orbitals for a Diels-Alder reaction. They additionally consider reaction energetics by (i) optimizing reactant, product and transition state structures, (ii) calculating activation energies, and (iii) calculating and visualising vibrations in the transition state. Using computational results students reason and predict which product preferentially forms under kinetic or thermodynamic control. All calculations are performed at theory levels comparable to current theoretical research. Practical work is completed within a four-hour laboratory period with evaluation of calculations and preparation of reports occurring outside class time.

Key Words: Computers in Chemistry; physical chemistry

(*) Corresponding author. (E-mail: sskoniec@chem.utoronto.ca)

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Supporting Materials:

Accompanying this manuscript contains the following: (i) background behind the Diels-Alder reaction; (ii) detailed notes for instructors and students and (iii) practical extensions of the described experiment (available in a Zip file) (1.63 MB)