With this award, the Chemical Structure, Dynamics and Mechanisms Program supports the work of Professor Edward L. Clennan at the University of Wyoming. The research will focus on the synthesis and characterization of 2nd generation dicationic light harvesting molecules. The highly charged frameworks of the 1st generation of these unique materials were designed to improve their efficiency as photoinduced electron transfer (PET) sensitizers by inhibiting energy wasting return electron transfer. The 2nd generation sensitizers that will be synthesized will have structural features that will improve their hydrolytic stabilities. They will also be partnered with a series of different charge balancing counterions in order to probe the counterion effect on reaction efficiencies. The photophysical and electrochemical characteristics of these new materials will be investigated and their abilities to increase the number of product molecules formed per photon used in several PET reactions will be determined. The ability of these new sensitizers to increase the chain length of a prototypical electron transfer chain reaction by inhibiting the chain termination step will also be examined. The value of these new sensitizers will also be demonstrated in several synthetically useful transformations.
These new sensitizers will provide access to greener, more environmentally friendly, higher efficiency photoinduced electron transfer reactions. These reactions have the far-reaching impact of being able to produce new materials that are difficult or impossible to obtain using other methods. In addition, these new sensitizers are themselves fascinating new materials that have potential uses in devices as diverse as molecular switches, field-effect transistors, organic photovoltaic devices, and organic light emitting diodes (OLEDs). Finally, the students who will work on this project will obtain valuable experience in a wide range of computational and experimental tools.
