Sharon Hammes-Schiffer is supported by an award from the Theoretical and Computational Chemistry program to continue her research into the development of new theoretical and computational approaches that will provide insight into the fundamental principles of the proton-coupled electron transfer (PCET) method. The objective of the first part of the project is the development of methodology to incorporate the proton donor-acceptor motion, explicit solvent and protein, and the corresponding dynamical effects into a theoretical formulation for PCET reactions. Model PCET systems are being designed to test the underlying assumptions and identify the range of validity for the various levels of theory. The objective of the second part of the project is to develop a nuclear-electronic orbital (NEO) method for calculating vibronic couplings in PCET reactions. The ability to calculate the couplings with the ab initio NEO method will provide greater predictive power for the PCET theory. The objective of the third project is to apply these approaches to a series of self-exchange reactions and to compare hydrogen atom transfer and PCET mechanisms. In terms of broader impacts of the proposed research, because PCET reactions are essential for a wide range of chemical and biological processes, including electrochemistry, photosynthesis, respiration, and enzyme reactions, the development of a theoretical framework for PCET reactions will significantly impact other fields in chemistry and biology. A new educational activity will be the development of hands-on science classes for elementary school students. The objective of these classes is to motivate young students in the areas of math, science, and computers.
