Electronic Coupling and Adiabaticity in Heterogeneous Electrode Transfer

该项目在分析和表面化学计划中得到支持，重点研究电子共轭在促进金属电极和位于电极表面已知距离处的氧化还原位点之间的远程电子转移中的作用。 这项工作的关键将是使用烷基硫醇与侧基二茂铁基团形成自组装单分子膜的金属电极表面。 亚苯基和萘部分将在沿烷基链的沿着各种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教授Creager和他的研究学生在克莱姆森大学将合成这些化合物，表征其结构后形成的自组装单分子膜，并研究其电子转移性能使用椭圆偏振法，反射吸收红外光谱，电位阶跃计时电流法，快速扫描循环伏安法，和快速电化学阻抗谱。 该项目将有助于理解生物电子转移反应的功能，测试长距离发生的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的动力学方面的相对贡献。 许多生物过程、电子材料和纳米催化结构需要在短时间内长距离发生电子转移反应。 当长距离电子转移过程快速时，能量的捕获、转换和随后的有效利用可以变得实用。 这个项目将涉及克莱姆森大学的研究生在确定快速电子转移反应的分子水平的要求。 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转移速率对距离的依赖性的现代理论。

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.