CAREER:Single-Molecule Spectroscopy as a Mechanistic Tool for Studying Catalyst Reaction Dynamics

该奖项由化学学部化学结构、动力学和机理b项目资助，将使威斯康星大学麦迪逊分校的Randall H. Goldsmith教授能够开发和应用工具，用于观察单个分子催化剂在周转条件下的不同步化学动力学。这些方法将能够确定瞬态中间体的形成和消耗动力学以及催化剂行为的时间波动，包括转移速率常数和对映体选择性。这些微观行为对体反应动力学的影响将被探讨。测量将通过时间分辨荧光显微镜进行。荧光团的设计、化学合成、等离子体纳米结构的制造和部署是这种方法的关键要素。总的来说，这些活动将允许确定催化的分子动力学年表，这将增加对反应机制的新见解，并指导未来催化剂开发的策略。在人类日常生活中所能进行的所有宏观观察之下，是一个在单个分子微观层面上搅动、充满活力和动态的世界。通过对单个分子进行测量，本提案试图消除宏观和微观世界之间的脱节，这有两个目的。首先，单分子的混沌本质掩盖了分子行为，而这些行为对工业上有用的化学反应具有重要影响。揭示单个催化剂分子的分子动力学，这些分子能够进行具有挑战性的化学反应，将使我们更好地理解它们的运作模式，为设计新的更有效的催化剂和更便宜、更“绿色”的化学指明道路。其次，消除这种脱节对化学教育有重要的影响，因为在宏观尺度上理解化学行为自然来自于在微观尺度上理解化学。很少有教育实验能让学生和非科学家真正“看到”单个分子。该方案包含了一个紧密结合的扩展活动，以建立一个强大的便携式显微镜，使用户能够用肉眼看到单个分子。这一教育工具将在博物馆和学校建立并用于新的化学教育倡议，包括那些在科学和技术职业中代表性不足的学生占很大一部分的学校。

This award, funded by the Chemical Structure, Dynamics, and Mechanisms-B Program of the Division of Chemistry, will enable Professor Randall H. Goldsmith of the University of Wisconsin Madison to develop and apply tools that enable the observation of unsynchronized chemical dynamics of individual molecular catalysts under turnover conditions. These methods will enable determination of the kinetics of formation and depletion of transient intermediates and temporal fluctuations of catalyst behavior, including shifting rate constants and enantioselectivity. The impact of these microscopic behaviors on bulk reaction dynamics will be explored. Measurements will be made via time-resolved fluorescence microscopy. Fluorophore design, chemical synthesis, and fabrication and deployment of plasmonic nanostructures are critical elements of this approach. Taken together, these activities will allow determination of a chronology of the molecular dynamics of catalysis that will add new insights on reaction mechanism and guide strategies for future catalyst development. Underneath all macroscopic observations that humans can make in everyday life is a churning, vibrant, and dynamic world at the microscopic level of single molecules. By making measurements on single molecules, this proposal endeavors to remove the disconnect between the macro- and micro-world for two purposes. First, the chaotic nature of single molecules hides molecular behavior that has important consequences for industrially useful chemical reactions. Revealing the molecular dynamics of individual catalyst molecules, molecules that enable challenging chemical reactions, will allow greater understanding of their mode of operation, leading the way to the design of new and more effective catalysts and cheaper and "greener" chemistry. Second, removing this disconnect has important consequences for chemical education, as understanding chemical behavior on the macro-scale flows naturally from understanding chemistry at the micro-scale. Few educational experiments exist that can allow students and non-scientists to truly "see" single molecules. This proposal contains a closely integrated outreach activity to build a robust and portable microscope that will allow users to see single molecules with the naked eye. This educational tool will be built and used for new chemical education initiatives in museums and schools, including those with large components of students under-represented in science and technology careers.