Electronic Coupling and Adiabaticity in Heterogeneous Electrode Transfer

该项目由分析和表面化学项目支持，重点研究电子共轭在促进金属电极和氧化还原位点之间的远程电子转移中的作用，这些位点位于距离电极表面已知的距离上。这项工作的关键将是使用烷基硫醇与悬垂的二茂铁基团在金属电极表面形成自组装的单层。苯炔和萘基团将在烷基链上的不同已知位置被取代，以改变电子共轭的位置。在这三年的持续资助中，Creager教授和他在克莱姆森大学的研究生将合成这些化合物，在形成自组装单层时表征它们的结构，并使用椭圆偏振法、反射吸收红外光谱、电位步进时序电流法、快速扫描循环伏安法和快速电化学阻抗谱法研究它们的电子转移特性。本项目将有助于理解生物电子转移反应的功能，测试长距离快速电子转移反应的理论和实验探针，并确定电子耦合和核动力学在控制这些过程动力学中的相对贡献。许多生物过程、电子材料和纳米级催化结构都需要在短时间内发生长距离的电子转移反应。当远距离电子转移过程快速时，捕获、转换和随后的能量有效利用就可以成为现实。该项目将涉及克莱姆森大学的研究生，以确定快速电子转移反应的分子水平要求。非常快速的电化学和光谱测量将用于测试和进一步发展电子传递速率与距离关系的现代理论。

This project, supported in the Analytical and Surface Chemistry Program, focusses on the study of the role of electronic conjugation in promoting long-range electron transfer between a metal electrode and redox site located at a known distance from the electrode surface. Key to this work will be the use of alkyl thiols with pendant ferrocene groups to form self assembled monolayers on metal electrode surfaces. Phenylene and naphthalene moieties will be substituted at various known positions along the alkyl chain to vary the position of electronic conjugation. During this three year continuing grant Professor Creager and his research students at Clemson University will synthesize these compounds, characterize their structure upon formation of self assembled monolayers, and study their electron transfer properties using ellipsometry, reflection-absorption infrared spectroscopy, potential step chronoamperometry, fast-scan cyclic voltammetry, and fast electrochemical impedance spectroscopy. This project will contribute to the understanding of the function of biological electron transfer reactions, test the theory and experimental probes of fast electron transfer reactions that occur over long distances, and determine the relative contributions of electronic coupling and nuclear dynamics in controlling the kinetics of these processes. Many biological processes, electronic materials, and nanoscale catalytic structures require electron transfer reactions that occur in short periods of time over long distances. The trapping, conversion, and subsequent efficient use of energy can become practical when long range electron transfer processes are fast. This project will involve research students at Clemson University in the determination of the molecular level requirements for fast electron transfer reactions. Very fast electrochemical and spectroscopic measurements will be used to test and further develop modern theories on the dependence of electron transfer rates on distance.