3 molecule to illustrate how " /> Chemical Reactivity: SOMO, HOMO, and LUMO|Introductory Organic Chemistry Course|Chemistry

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Introductory Organic Chemistry - Lecture 15

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Lecture 15 - Chemical Reactivity: SOMO, HOMO, and LUMO

Professor McBride begins by using previous examples of "pathological" bonding and the BH3 molecule to illustrate how a chemist's use of localized bonds, vacant atomic orbitals, and unshared pairs to understand molecules compares with views based on the molecule's own total electron density or on computational molecular orbitals. This lecture then focuses on understanding reactivity in terms of the overlap of singly-occupied molecular orbitals (SOMOs) and, more commonly, of an unusually high-energy highest occupied molecular orbital (HOMO) with an unusually low-energy lowest unoccupied molecular orbital (LUMO). This is shown to be a generalization of the traditional concepts of acid and base. Criteria for assessing reactivity are outlined and illustrated.

Prof. J. Michael McBride
CHEM 125: Freshman Organic Chemistry, Fall 2008
(Yale University: Open Yale)
Date accessed: 2009-11-11
License: Creative Commons BY-NC-SA

Lecture Material

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Supplementary lecture material is listed below.

1. BH3, an Example of an MO Computation & an Apology for Local Bonds
2. MO Interactions, which ones count? (HOMO/LUMO)
3. Functional Groups (high HOMO base / low LUMO acid)



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