Path Integral Theory of Electron Transfer in Chemical and Biological Systems

麦志豪博士获得理论和计算化学项目的资助，研究在各种化学和生物体系中发生的电子转移反应。完全量子力学理论将被用来研究核隧道效应，表现在倒区的水电子转移反应和正常区的高度非绝热反应中的同位素效应。为了了解Creutz-Taube化合物的光谱性质，将通过直接模拟来研究可能涉及高度离域电子的相干介导的转移机制。最后，关于相干的可能作用和光合作用反应中心中间态的影响的问题将用全动态量子蒙特卡罗方法来解决。电子转移反应普遍存在于许多化学和生物过程中。所有氧化还原反应的基础是电子从一种化学物种迅速转移到另一种化学物种的过程。一个非常重要的电子传递系统发生在植物和一些细菌的光合作用反应中心。由于电子是一个非常轻的粒子，这些转移过程必须用量子理论来处理，以解释发生的非经典隧穿。麦晋桁的研究将有助于阐明这种隧穿电子转移过程的量子力学本质。

Dr. Chi Ho Mak is supported by a grant from the Theoretical and Computational Chemistry Program to study electron transfer reactions occurring in various chemical and biological systems. Fully quantum mechanical theories will be used to study nuclear tunneling as manifested in the isotope effect in aqueous electron transfer reactions in the inverted region and highly nonadiabatic reactions in the normal region. The mechanism of coherence-mediated transfers involving a possibly highly delocalized electron will be investigated by direct simulations to understand the spectroscopic properties of Creutz-Taube compounds. Finally, questions concerning the possible role of coherence and the effects of an intermediate state in the photosynthetic reaction center will be addressed by fully dynamical quantum Monte Carlo methods. %%% Electron transfer reactions are ubiquitous in many chemical and biological processes. Underlying all oxidation reduction reactions is a process in which an electron is rapidly transferred from one chemical species to another. One very important electron transfer system occurs in the photosynthetic reaction center of plants and some bacteria. Since the electron is a very light particle these transfer processes must be treated using quantum theory to account for the nonclassical tunneling which takes place. Mak's research will help to elucidate the quantum mechanical nature of this tunneling electron transfer process.