12. Overlap and Atom-Pair Bonds

Freshman Organic Chemistry (CHEM 125)

This lecture begins by applying the united-atom "plum-pudding" view of molecular orbitals, introduced in the previous lecture, to more complex molecules. It then introduces the more utilitarian concept of localized pairwise bonding between atoms. Formulating an atom-pair molecular orbital as the sum of atomic orbitals creates an electron difference density through the cross product that enters upon squaring a sum. This "overlap" term is the key to bonding. The hydrogen molecule is used to illustrate how close a simple sum of atomic orbitals comes to matching reality, especially when the atomic orbitals are allowed to hybridize.

00:00 - Chapter 1. The United-Atom "Plum-Pudding" View for Ethane and Methanol
13:24 - Chapter 2. The Orbital Shape of 1-Flouroethanol
19:37 - Chapter 3. Localized Pairwise Bonding Between Atoms and the Idea of Overlap
36:36 - Chapter 4. Hydrogen at Bonding Distance: A Case for Overlap

Complete course materials are available at the Open Yale Courses website: http://open.yale.edu/courses

This course was recorded in Fall 2008.