Dynamics and Mechanisms of Electron Delocalization over Supramolecular Mixed Valence Systems

超分子混合价体系电子离域动力学和机制

• 批准号: 1461632
• 负责人: Clifford Kubiak
• 金额: $ 50.7万
• 依托单位: University of California-San Diego
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-07-01 至 2018-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1461632&HistoricalAwards=false
• 关键词: Dynamics; Mechanisms; Electron; Delocalization; over

In this project funded by the Chemical Structure, Dynamic & Mechanism B Program of the Chemistry Division, Professor Clifford P. Kubiak of the Department of Chemistry & Biochemistry at the University of California, San Diego (UCSD) will develop and study new systems that undergo ultrafast chemical reactions, those that occur in one-trillionth of a second (1 picosecond) over large supramolecular structures. The goal of this research is to develop molecular devices by the self-assembly of large materials with specific functions related to information storage and switching. The supramolecular mixed valence complexes that will be studied in this project and studies of the dynamics of electron transfer across them offer a chemistry-driven approach to assembling complex structures that can gate, store, and transfer charges. The study of these systems will likely influence and guide broader thought about the specific chemical, physical, and engineering issues that will bring molecular electronic based devices into the mainstream, and findings will be widely disseminated. The project will continue to involve undergraduate students through the UCSD undergraduate research mentor program. The project will also be interfaced with existing outreach programs at UCSD for the recruitment of underrepresented students. There will also be a strong international collaboration with a research group at the University of Uppsala, Sweden.The study of electron transfer processes through non-covalent interactions is important to the broader understanding of how long-range electron transfer occurs in natural and artificial supramolecular systems. This project builds on discoveries from the immediately preceding NSF support period. Specifically, it will involve experimental studies of the dynamics and mechanisms of electron delocalization in supramolecular mixed valence complexes. Synthetic studies will be directed toward the preparation of new supramolecular assemblies linked by weak non-covalent interactions including hydrogen bonds and pi-stacked organic structures. These will be used to test theories of the relationship between infrared spectral lineshape and the dynamical mechanism for electron transfer in mixed valent systems. Studies of ultrafast electron transfer in supramolecular complexes will be conducted to determine the timescale and mechanism of delocalization of an electron after its injection into a supramolecular assembly. This project seeks to explore a new concept in the assembly of complex structures - the use of electron delocalization to "harden" weak interactions like hydrogen bonds to produce more stable assemblies, and position them for more permanent forms of chemical attachment.

在这个由化学系化学结构、动力学和机理 B 项目资助的项目中，加州大学圣地亚哥分校 (UCSD) 化学与生物化学系的 Clifford P. Kubiak 教授将开发和研究经历了超快化学反应，即在大型超分子结构上以万亿分之一秒（1 皮秒）发生的反应。这项研究的目标是通过自组装大型材料来开发具有与信息存储和交换相关的特定功能的分子器件。本项目将研究的超分子混合价络合物以及对它们之间电子转移动力学的研究提供了一种化学驱动的方法来组装可以门控、存储和转移电荷的复杂结构。对这些系统的研究可能会影响和指导对特定化学、物理和工程问题的更广泛思考，这些问题将使基于分子电子的设备进入主流，并且研究结果将被广泛传播。该项目将继续通过加州大学圣地亚哥分校本科生研究导师计划让本科生参与。该项目还将与加州大学圣地亚哥分校现有的外展项目相结合，以招募代表性不足的学生。还将与瑞典乌普萨拉大学的一个研究小组开展强有力的国际合作。通过非共价相互作用研究电子转移过程对于更广泛地理解天然和人造超分子中如何发生长程电子转移非常重要系统。该项目建立在前一个 NSF 支持期间的发现之上。 具体来说，它将涉及超分子混合价络合物中电子离域动力学和机制的实验研究。合成研究将针对通过弱非共价相互作用（包括氢键和π堆积有机结构）连接的新型超分子组装体的制备。这些将用于测试红外光谱线形与混合价系统中电子转移动力学机制之间关系的理论。将进行超分子复合物中超快电子转移的研究，以确定电子注入超分子组装体后离域的时间尺度和机制。 该项目旨在探索复杂结构组装的新概念 - 使用电子离域来“硬化”氢键等弱相互作用，以产生更稳定的组装体，并将其定位为更永久形式的化学附着。