Freshman Organic Chemistry II with Michael McBride - 32. Measuring Bond Energies: Guest Lecture by Prof. G. Barney Ellison

Freshman Organic Chemistry II (CHEM 125B) Spectroscopic determination of bond dissociation energies is relatively straightforward for many diatomic molecules, but for polyatomic molecules it requires merging the results from a variety of challenging experiments. Professor Ellison describes how such techniques as flowing-afterglow mass spectroscopy and negative-ion photoelectron spectroscopy together with data on free-radical kinetics and heats of formation have allowed precise determination of the O-H, C-H, and C-O bonds in methanol and other compounds. Interpreting these reliable data provides new insight into the nature of chemical bonding and "resonance". 00:00 - Chapter 1. Diatomic Bond Dissociation Energy from Spectroscopy 01:28 - Chapter 2. O-H BDE from Acidity in the Flowing Afterglow 12:35 - Chapter 3. C-H BDE from Radical Equilibrium 18:34 - Chapter 4. C-O BDE from Radical Heats of Formation. Potential Errors 23:20 - Chapter 5. Interpreting BDEs 35:43 - Chapter 6. Questions: Hot Bands and Resonance Stabilization Complete course materials are available at the Open Yale Courses website: http://oyc.yale.edu This course was recorded in Spring 2011.