Charge transport through single redox molecules and water bridges

该项目将得到化学结构、动力学和机理计划(CSDM)以及化学系的高分子、超分子和纳米化学计划(MSN)的支持。在这项研究中，亚利桑那州立大学的陶农建教授和他的研究小组将开发单分子断裂连接技术来研究多芳烃分子和水形成的分子桥结构的电子电导。研究单分子中的电子传输是迈向以单分子为基础的电子器件的最终目标的必要步骤，也是更好地理解许多化学和生物过程的关键，如电化学反应、呼吸和生物能量学。这个项目将解决的重要问题包括：通过单个分子进行的最有效的电子传输是什么？限制我们实现最有效的电子传输的因素是什么？如何理解和克服这些限制因素，从而控制电荷传输效率？为了对生物和电化学系统中的电子传递现象产生直接影响，人们必须了解水分子在电子传递中的作用。因此，该项目还将解决有关水分子的问题：是否有可能直接测量两个电极之间水分子氢键网络的形成？如果是这样的话，不同的氢键水桥网络的电导率是多少？与网络相关的不同电子传输路径之间是否存在量子干扰？为了向学生提供跨学科和国际培训经验，该项目将利用几个在校本科生和研究生研究项目，从化学和其他项目招收和培训学生；接待国际学生并与国际研究人员合作；通过与当地少数族裔招生人数较多的公立学校合作，启动社区外联计划。

This project will be supported by the Chemical Structure, Dynamics, and Mechanisms Program (CSDM) and the Macromolecular, Supramolecular and Nanochemistry Program (MSN) of the Division of Chemistry. In this study, Professor Nongjian Tao and his research group at Arizona State University will develop single molecule break-junction techniques to study electronic conductance through polyaromatic hydrocarbon molecules and molecular bridge structures formed from water. Studying electron transport in single molecules is a necessary step towards the ultimate goal of building electronic devices based on single molecules, and it is also critical for a better understanding of many chemical and biological processes, such as electrochemical reactions, respiration and bioenergetics. Important questions that this project will address include: What is the most efficient electron transport via a single molecule? What are the factors that limit us from achieving the most efficient electron transport? How can one understand and overcome these limiting factors, thus controlling the charge transport efficiency? In order to have a direct impact on electron transfer phenomena in biological and electrochemical systems, one must understand the role of water molecules in electron transport. This project will thus address also questions regarding water molecules: Is it possible to directly measure the formation of hydrogen-bonded networks of water molecules between two electrodes? If so, what are the conductivities of different hydrogen-bonded networks of water bridges? Is there quantum interference between different electron transport pathways associated with the networks? In order to provide students with interdisciplinary and international training experience, this project will leverage several on-campus undergraduate and graduate research programs to recruit and train students from chemistry and other programs; host international students and collaborate with international researchers; and start a community outreach program via working with local public schools that have large minority enrollments.