66287 - Reaction Mechanisms

Learning outcomes

At the end of the class the student will be able of using the most common tools of physical organic chemistry (transition state theory, chemical kinetics, free energy relationships, isotopic effects…) and theoretical organic chemistry (frontier orbital theory, Woodward-Hoffmann theory, valence-bond theory) to understand the mechanism of organic reactions.

Course contents

Born-Oppenheimer approximation. Potential energy surface (PES). Mathematical description of a PES for structural and reactivity problems in organic chemistry. Critical points. How to represent a PES: cross sections, More O'Ferrall diagrams. Perturbation methods in organic chemistry: the PMO (Perturbation Molecular Orbital) method. HSAB theory in organic chemistry: understanding HSAB theory using the PMO approach. Chemical kinetics: first and second order reactions, consecutive reactions. Transition state theory. Free energy relationships. Isotope effects. Application of PMO theory to organic reactivity: the FMO ((Frontier Molecular Orbital) approximation. Substitution nucleophilic reactions at the sp3 carbon. Pericyclic reactions (cycloaddition, electrocyclic, sigmatropic, chelotropic reactions): basic notions. Woodward-Hoffmann rules for  electrocyclic and cycloaddition reactions. FMO theory for electrocyclic, cycloaddition, sigmatropic and chelotropic reactions. A detailed comparison between theory and experiments for pericyclic reactions.

Readings/Bibliography

Teacher notes. Papers available in literature

Teaching methods

Lectures. Problem solving in the classroom

Assessment methods

The goal of the oral examination can be summarized as follows:
(i) the student must possess a good knowledge of the main tools (experimental and theoretical) that allow to understand the topology of a reaction surface.
(ii) the student must be able to use the above concepts to discuss simple examples of organic reactivity.

Teaching tools

Problem solution in the classroom

Office hours

See the website of Andrea Bottoni