CHEM 125a - Lecture 33 - Conformational Energy and Molecular Mechanics

Lecture 33 - Conformational Energy and Molecular Mechanics

Overview

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.

Resources

Professor McBride's web resources for CHEM 125 (Fall 2008)

http://webspace.yale.edu/chem125_oyc/#L33

This website may include third-party materials pertaining to relevant topics, provided for the user's convenience. Yale does not control or take responsibility for the content of any off-site pages or linked sites.

Assignment

Reading assignments, problem sets, PowerPoint presentations, and other resources for this lecture can be accessed from Professor McBride's on-campus course website, which was developed for his Fall 2008 students. Please see Resources section below.

Course Media

Transcript

html

Audio

mp3

Low Bandwidth Video

mov [100MB]

High Bandwidth Video

mov [500MB]