Gated Electron Transfer in Copper(II)/(I) Systems

Wayne州立大学的David Rohrabacher和Akron大学的Michael Taschner受到无机、生物无机和有机金属化学计划的支持，研究配位位几何形状对铜（Cu(I)）和铜（Cu(II)）配合物电子转移反应速率的影响。研究的主要重点将是探索约束一个或两个铜中心几何形状的配体如何影响两个铜原子之间电子转移（ET）的动力学和机制。主要研究方向是溶剂分子对大环配体和三足配体配合物ET速率的影响，模拟特定铜蛋白配位的三角配体和三角锥体配体的作用，以及涉及大环配体的反应中亚稳中间体的重组障碍。同时，还将研究含钌和铜的相关配合物中的电子转移反应。用于这些研究领域的新配体将在阿克伦大学合成。动力学、电化学和光谱研究将在韦恩州立大学进行。涉及过渡金属离子的电子转移反应在工业化学和生物化学的许多领域以及新兴的分子电子学领域都具有核心重要性。本研究的重点是已知在或多或少程度上由金属离子第一配位壳的构象变化控制的速率过程。这种类型的过程也被认为（有时是相当试探性的）在许多具有实际意义的更复杂的系统中起着主要作用。本项目研究的相对不复杂的案例特别适合于发展和测试理解，然后可以应用于更复杂的案例，这些案例在生物和技术应用中具有核心重要性。

David Rohrabacher of Wayne State University and Michael Taschner of the University of Akron are supported by the Inorganic, Bioinorganic, and Organometallic Chemistry Program for research on effects of coordination site geometry on rates of electron transfer reactions of cuprous (Cu(I)) and cupric (Cu(II)) complexes. The main focus of the research will be to explore how ligands that constrain geometry about one or both copper centers influence the kinetics and mechanism of electron transfer (ET) between the two copper atoms. Main interest will be on the influence of solvent molecules on the ET rates of complexes involving macrocyclic and tripodal ligands, effects of trigonal and trigonal-pyramidal ligands that mimic coordination sites in specific copper proteins, and reorganization barriers in metastable intermediate species in reactions that involve macrocyclic ligands. Electron transfer reactions in related complexes containing both ruthenium and copper will also be investigated. New ligands to be used in each of these research areas will be synthesized at The University of Akron. Kinetic, electrochemical and spectroscopic studies will be performed at Wayne State University.Electron transfer reactions involving transition metal ions are of central importance in many areas of industrial chemistry and biochemistry and also in the emerging field of molecular electronics. This study focuses on rate processes that are known to be controlled, in greater or less degree, by conformational changes in the first coordination shells of the metal ions. This type of process has also been identified (sometimes quite tentatively) as playing a major role in many more-complex systems of practical interest. The relatively uncomplicated cases that are studied in this project are exceptionally suitable for developing and testing understandings that can then be applied to the more complicated cases that are of central importance in biological and technological applications.