CHEM 214 Lecture Notes - Lecture 33: Singlet Oxygen, Molecular Orbital Diagram, Molecular Electronic Transition

• School: McGill University
• Department: Chemistry
• Course: CHEM 214
• Professor: Anthony Mittermaier

Document Summary

We have looked only at situations where the molecule does not undergo any dissociative processes. If a molecule absorbs a photon and ends up with energy than the de of a particular electronic state, it will dissociate. Transitions into energy levels higher would have a continuous range of possible energies. In many scenarios, you are able to absorb photon of energy sufficient to populate molecule with more energy than confining potential has in excited state, hence molecule will dissociate. Depending on the wavelength of light, oxygen can dissociate producing reactive species. This process is important in atmospheric chemistry for ozone production. Uv light is generally dangerous because most molecules can undergo some types of similar process when they absorb high energy photons. Mo diagram for regular o2, we have populated the pi* with two electrons with parallel spin, hence lowest electronic state of oxygen is a triplet state.