Molecular Interrogation of Coupled Electron- and Phase-Transfer Reactions

在化学系化学结构、动力学和机制A（CSDM-A）项目的支持下，犹他州大学的罗德里戈·诺列加（Rodrigo Noriega）沿着犹他州大学的亨利·怀特（Henry White）和芝加哥大学的格雷戈里·沃斯（Gregory Voth）将研究耦合电子和相转移过程。这些反应，其中电子转移与离子或中性分子穿过相边界的运输一起发生，存在于各种各样的工业过程和能量存储技术中。理解这些反应是具有挑战性的，因为缺乏分子尺度的理解中间体在这些多步骤的过程中的关键步骤。Noriega博士和他的团队将在定义明确的分子系统上整合超快光谱和电化学实验，并使用计算方法独立研究耦合电子和相转移反应。对这些反应的深入了解有可能影响能量储存和稀有金属离子分离。除了对学生进行研究培训外，该团队还将组织年度研讨会，其中包括实验室演示和专业发展机会。复杂界面处的探针反应，即氧化还原活性分析物与电极发生电子转移，同时由于其氧化态的溶解度不同而在两个不混溶相之间转移，将通过三相界面处的伏安法进行研究，以及通过超快瞬态吸收光谱和多尺度电化学分子动力学模拟。为了告知和测试捕获分子尺度动力学和宏观结果的新模型，将采用一个分层框架，该框架将计算与光谱和电化学观察相结合，跨越时间和长度的数量级。溶剂化壳交换的能量学和动力学，包括在界面处的波动的作用，将通过相关的相特定的电化学响应，时间分辨的吸收和发射测量在受控的静电条件下的相边界，和多尺度分子动力学模拟来确定。在明确定义的界面处独立监测离子和电子转移电流，同时系统地改变其双电层结构，沿着高效的恒电位电化学模拟，将确定分子结构的作用，相关的耦合电子和相转移反应在三个-该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的评估来支持。影响审查标准。

With support from the Chemical Structure, Dynamics, and Mechanisms A (CSDM-A) Program in the Division of Chemistry, Rodrigo Noriega of the University of Utah along with Henry White from the University of Utah and Gregory Voth from the University of Chicago will study coupled electron and phase transfer processes. These reactions, where electron transfer occurs alongside the transport of ions or neutral molecules across a phase boundary, are present in a wide variety of industrial processes and energy storage technologies. Understanding these reactions is challenging due to the lack of molecular-scale understanding of intermediates at critical steps in these multistep processes. Dr. Noriega and his team will integrate ultrafast spectroscopy and electrochemistry experiments on well-defined molecular systems with computational methods to study coupled electron and phase transfer reactions independently. The resulting insight into these reactions has the potential to impact energy storage and rare metal ion separations. In addition to training students in research, the team will organize an annual workshop that includes lab demonstrations and professional development opportunities.Probe reactions at complex interfaces, whereby redox-active analytes undergo electron transfer with an electrode while also transferring between two immiscible phases due to the differential solubility of their oxidation states, will be studied with voltammetry at three-phase interfaces, as well as by ultrafast transient absorption spectroscopy, and multiscale electrochemical molecular dynamics simulations. To inform and test new models that capture molecular-scale dynamics and macroscopic outcomes, a hierarchical framework that combines computation with spectroscopic and electrochemical observation spanning orders of magnitude in time and length will be employed. The energetics and dynamics of solvation shell exchange, including the role of fluctuations at the interface, will be determined by correlating phase-specific electrochemical responses, time-resolved absorption and emission measurements at phase boundaries under controlled electrostatic conditions, and multiscale molecular dynamics simulations. Independently monitoring the ion- and electron-transfer currents at well-defined interfaces while systematically altering their electric double layer structure, along with efficient constant-potential electrochemical simulation, will identify the role of molecular structure of relevant coupled electron and phase transfer reactions at three-phase interfaces.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.