Quantum Charge Tunneling through Self-Assembled Monolayers (SAMs)

在化学系大分子、超分子和纳米化学（MSN）项目的支持下，哈佛大学的George Whitesides教授正在研究电子如何在分子中传输。电子不像在金属中流动那样在分子中移动。相反，它们会通过隧道。隧穿是一种量子力学行为，只适用于非常小的粒子，比如电子。电子在分子中隧穿的长度和效率取决于分子的结构和化学键的排列。然而，研究电子在分子中的隧穿是一个重大的挑战，因为它需要将两个电极分开相当于单个分子长度的距离。怀特塞兹教授和他的团队将开发新的方法来研究有机和生物有机物质中的量子隧道效应。他们的发现可能会导致新的电子设备和传感器，以及更好地理解分子催化和催化电子传递的酶。这个高度跨学科的项目还将通过培训博士后学者如何结合化学、生物学和物理学的概念、技术和工具，为未来科学和技术劳动力的发展做出贡献。该项目将推进用于表征有机自组装单层（SAMs）量子隧道的液体共晶镓铟（eGaIn）电极系统。表面等离子体光谱，x射线光电子能谱（XPS）和原子力显微镜（AFM）将用于将结构特征与观察到的电化学行为联系起来。该项目旨在将隧穿速率与分子电子结构联系起来，并了解外加电场和磁场对隧穿电流的影响。液体环境中生物相关sam的研究将提供对周围液体（和溶解离子）在电荷传导中的作用的见解，并为生物有机系统中的电子转移速率建立基础。对嵌入催化剂的SAMs的研究将考察定向电场对催化转化的影响。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

With support from the Macromolecular, Supramolecular, and Nanochemistry (MSN) Program in the Division of Chemistry, Professor George Whitesides of Harvard University is studying how electrons are transported through molecules. Electrons do not move through molecules like they do when they flow through a metal. Instead, they tunnel through them. Tunneling is a quantum mechanical behavior that pertains only to very small particles, like electrons. The length that an electron can tunnel through a molecule, and how efficiently it can do it, depends on the molecule's structure and the arrangement of the chemical bonds. However, studying electron tunneling through molecules presents a significant challenge, as it requires separating two electrodes by a distance equivalent to the length of a single molecule. Professor Whitesides and his group will develop new methods for studying quantum tunneling in organic and bioorganic matter. Their discoveries could lead to new electronic devices and sensors, as well as a better understanding of molecular catalysis and enzymes that catalyze electron transport. This highly interdisciplinary project will also contribute to the development of the future science and technology workforce by training postdoctoral scholars on how to combine concepts, techniques, and tools in chemistry, biology, and physics.The project will advance the liquid eutectic Gallium-Indium (eGaIn) electrode system for characterizing quantum tunneling in organic self-assembled monolayers (SAMs). Surface plasmon spectroscopy, x-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM) will be used to relate structural features to observed electrochemical behavior. The project aims to correlate rates of tunneling with molecular electronic structure and understand the effects of applied electric and magnetic fields on tunneling currents. Studies of bio-relevant SAMs in liquid environments will provide insights into the role surrounding liquids (and dissolved ions) play in charge conduction and establish a basis for electron-transfer rates in bioorganic systems. Studies of SAMs with embedded catalysts will examine the effect of oriented electric fields on catalytic transformations.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.