With this renewal award, the Organic and Macromolecular Chemistry Program continues its support of the work of Professor Michael R. Wasielewski of the Department of Chemistry, Northwestern University, Evanston, IL. The research will extend the PI's research on the design and synthesis of novel molecular materials with the capability of undergoing light induced electron transfer to generate radical ion pairs. Taking advantage of the fact that the properties of radical pairs are affected by magnetic fields, an internal magnetic field in the form of a stable free radical will be incorporated. The effect of the additional unpaired spin and the ability to turn this spin on and off on electron and spin transfer will be investigated. These studies will provide fundamental knowledge concerning intramolecular interactions among unpaired electron spins that will aid in the design of systems for harvesting solar energy and for use in molecular optoelectronics. The project will provide important training for undergraduate and graduate students with an emphasis on women and underrepresented minorities.