CHEM 125A - Freshman Organic Chemistry I
Lecture 33 - Conformational Energy and Molecular Mechanics. Understanding conformational relationships makes it easy to draw idealized chair structures for cyclohexane and to visualize axial-equatorial interconversion. After quantitative consideration of the conformational energies of ethane, propane, and butane, cyclohexane is used to illustrate the utility of molecular mechanics as an alternative to quantum mechanics for estimating such energies. To give useful accuracy this empirical scheme requires thousands of arbitrary parameters. Unlike quantum mechanics, it assigns strain to specific sources such as bond stretching, bending, and twisting, and van der Waals repulsion or attraction. (from oyc.yale.edu)
| Lecture 33 - Conformational Energy and Molecular Mechanics |
| Time | Lecture Chapters |
| [00:00:00] | 1. The 1918 Ernst Mohr Illustrations of Cyclohexane |
| [00:09:41] | 2. The Invention of Conformational Analysis |
| [00:22:25] | 3. Conformational Animations of Ethane, Propane, and Butane |
| [00:32:06] | 4. Molecular Mechanics as an Alternative to Quantum Mechanics |
| [00:40:13] | 5. Assigning Strain to Estimate Energy in Bonds |
| References |
| Lecture 33 - Conformational Energy and Molecular Mechanics Instructor: Professor J. Michael McBride. Resources: Professor McBride's website resource for CHEM 125 (Fall 2008). Transcript [html]. Audio [mp3]. Download Video [mov]. |
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