Theory of pi-Electron Compounds 1200-2SPEC182M
Application of the molecular-orbital (MO) theory to the description of the ground-state, and ionic and excited states of molecules. The definition and characteristics of the pi-electron molecules. The pi-electron approximation in the MO theory. The Pariser-Parr-Pople (PPP) model, the problem of empirical parameters. The description of electronic exitations of pi-electron molecules within the PPP model. The alternancy symmetry as a hidden symmetry of pi-electron hydrocarbons; the alternant and nonalternant hydrocarbons. A hierarchy of the pi-electron models: from the PPP model, through the Hubbard one, to the models based on the Hückel model. The introduction of the Hückel-Su-Schrieffer-Heeger (HSSH) model and its application in the description of geometry (the bond lengths) and energy of the pi-electron hydrocarbons and carbon molecules (fullerenes and nanotubes). Electric and magnetic properties of pi-electron molecules. The application of the HSSH model to the description of the charge distribution in nonalternant hydrocarbons. The interaction of ring-shaped pi-electron hydrocarbons with magnetic field (the HSSH model), the ring currents. Chemical reactivity of pi-electron molecules, reactivity indices. Wheland's ?-complex model. Pericylic reactions and the conservation of molecular symmetry (the Woodward-Hoffmann rules). The notion of aromaticity of sigma-eletron molecules - its various aspects.
Type of course
Mode
Prerequisites (description)
Learning outcomes
1. Learning the basic concepts of the quantum theory of molecules - using the example of pi-electron molecules.
2. Handling the simplest numerical models ot the theory of the pi-electron compounds (without the computer assistance).
Assessment criteria
In order to get a positive grade, the students have to solve two homework problems. The final grade is based on their performance with the problems, and on a short oral exam.
Practical placement
Not planned.
Bibliography
1. A. Streitwieser, Jr., "Molecular orbital theory for organic chemists", Wiley, New York, 1961.
Additional information
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