Theoretical Studies of Proton-Coupled Electron Transfer Reactions

Sharon Hammes-Schiffer获得了理论和计算化学项目的奖励，继续研究新的理论和计算方法的发展，这将为质子耦合电子转移（PCET）方法的基本原理提供见解。项目第一部分的目标是开发一种方法，将质子供体-受体运动、显式溶剂和蛋白质以及相应的动力学效应纳入PCET反应的理论公式。正在设计PCET模型系统，以测试基本假设并确定不同层次理论的有效性范围。项目第二部分的目标是开发一种核电子轨道（NEO）方法来计算PCET反应中的振动耦合。用从头算近地天体方法计算耦合的能力将为PCET理论提供更大的预测能力。第三个项目的目标是将这些方法应用于一系列自交换反应，并比较氢原子转移和PCET机制。由于PCET反应对于包括电化学、光合作用、呼吸作用和酶反应在内的广泛的化学和生物过程至关重要，因此PCET反应理论框架的发展将对化学和生物学的其他领域产生重大影响。一项新的教育活动将是为小学生开发动手科学课程。这些课程的目的是激发年轻学生在数学、科学和计算机领域的兴趣。

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.