Description:
| Aims & Learning Objectives: To revise some basic concepts in physical organic chemistry and develop a number of ideas used to correlate reactivity and mechanism in a range of organic reactions. After studying the Unit, students should be able to:
* Describe some experimental tools for investigating reaction mechanisms and the use of some theoretical models for their correlations and interpretation.
* Suggest solutions for complex problems involving combinations of numerical and mechanistic information from a variety of sources.
* Propose appropriate experimental approaches for determination of organic reaction mechanisms.
Content: Energy changes in equilibria and reactivity. Transition states and saddle points. Activation parameters. Analysis of reaction coordinates. Principle of Least Nuclear Motion. Hammond Postulate. More O'Ferrall - Jencks diagrams. Rate - equilibrium correlations. Hammett equation as an example of a linear free-energy relationship. Significance of s and r for reactivity and mechanism. Complex Hammett plots: change in mechanism vs. change in rate-determining step. Equilibrium and kinetic isotope effects. Primary and secondary effects and their significance. Heavy-atom effects. Solvent isotope effects.
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