Path Integral Theory of Electron Transfer in Chemical and Biological Systems

麦志浩博士获理论及计算化学计划资助，研究各种化学及生物系统中的电子转移反应。完全量子力学理论将被用于研究核隧穿，体现在倒转区的水电子转移反应中的同位素效应和正常区的高度非绝热反应中。通过直接模拟来研究可能涉及高度离域电子的相干介导转移的机制，以了解Creutz-Taube化合物的光谱特性。最后，关于相干的可能作用和光合反应中心中间态的影响的问题将通过完全动态量子蒙特卡罗方法来解决。电子转移反应在许多化学和生物过程中是普遍存在的。所有氧化还原反应的基础都是一个电子从一种化学物质迅速转移到另一种化学物质的过程。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反应中心。由于电子是一种非常轻的粒子，这些转移过程必须用量子理论来解释所发生的非经典隧穿。Mak的研究将有助于阐明这种隧穿电子转移过程的量子力学性质。

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.