Combined Single-Molecule Raman and Conductance Spectroscopies for Understanding Electric Field-Controlled Chemistry

结合单分子拉曼光谱和电导光谱来了解电场控制化学

• 批准号: 2239226
• 负责人: Joshua Hihath
• 金额: $ 44.5万
• 依托单位: Arizona State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-01 至 2025-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2239226&HistoricalAwards=false
• 关键词: Combined; Single; Molecule; Raman; Conductance

With support from the Chemical Measurement and Imaging (CMI) program and partial co-funding from the Chemical Structure, Dynamics, and Mechanisms - B (CSDM-B) program in the Division of Chemistry, Joshua Hihath and his research team at the University of California, Davis aim to understand the effects of applied external electric fields on molecular switching processes. As electric fields are emerging as “smart reagents” that can selectively catalyze reactions, understanding their role in chemical reactions is critical. The Hihath group is working to develop a novel and powerful approach for simultaneously applying an electric field and quantitatively measuring the effect of this field before, during, and after a chemical process. Their approach leverages a recently developed system for performing single-molecule Raman spectroscopy and conductance measurements simultaneously. The ability to track the effects of electrical and optical fields, charge transfer, and heating on individual molecules will impact a broad range of fields where controlling chemical processes is important. The project is providing research opportunities for graduate and undergraduate researchers, including individuals actively recruited from groups underrepresented in STEM (science, technology, engineering and mathematics).The combination of Raman spectroscopy with single-molecule electrical measurements provides detailed information about the configuration, binding energy, mechanical strain, vibrational modes, and local effective temperature in a single molecule bound between two electrodes. This multidimensional information allows resolution of electric field, mechanical, charge transfer, and heating effects on chemical processes occurring within the molecule. This project sets out to probe the mechanisms by which two distinctive single-molecule photoswitches undergo conformational changes in an applied field. The study will provide information about how the electrical field enables bypassing orbital symmetry selection rules, and how these processes differ from photochemical switching processes. Specific objectives include i) in situ identification of electrically controlled isomerization processes in single-molecule systems from the Raman signature of a molecule bound to two electrodes; ii) improved understanding of the effects of electric field orientation and magnitude on bond reorganization and transition states during electrical isomerization processes; iii) determination of the interplay between applied field and mechanical strain on isomerization processes; and iv) disambiguation between current-driven and field-driven isomerization processes.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.

在化学测量和成像计划（CMI）计划的支持下，并获得了从化学结构，动力学和机制的部分共同资助-B（CSDM-B）在化学系中的B（CSDM-B）计划，Joshua Hihath及其加利福尼亚大学的研究团队，戴维斯的旨在了解应用外部电场对分子开关过程的影响。由于电场正在成为可以选择性催化反应的“智能试剂”，因此了解它们在化学反应中的作用至关重要。 Hihath组正在努力开发一种新颖而有力的方法，以简单地应用电场并定量测量化学过程之前，期间和之后的效果。他们的方法利用了最近开发的系统，用于简单地进行单分子拉曼光谱和电导测量。跟踪电场和光场的影响，电荷转移以及对单个分子的加热的能力将影响控制化学过程很重要的广泛磁场。 The project is providing research opportunities for graduate and undergraduate researchers, including individuals actively recruited from groups underrepresented in STEM (science, technology, engineering and mathematics).The combination of Raman spectroscopy with single-molecule electrical measurements provides detailed information about the configuration, binding energy, mechanical strain, vibrational modes, and local effective temperature in a single molecule bound between two electrodes.该多维信息允许分辨出对分子内发生的化学过程的电场，机械，电荷转移和加热效应。该项目旨在探测两个独特的单分子照片开关在应用领域中均匀变化的机制。该研究将提供有关电场如何启用绕过轨道对称选择规则的信息，以及这些过程与光化学切换过程有何不同。特定对象包括i）原位鉴定单分子系统中电气控制的异构化过程，从结合到两种电气的分子的拉曼特征。 ii）提高了对电场定向和幅度对电气异构化过程中键重组和过渡状态的影响的理解； iii）确定异构化过程上应用场与机械应变之间的相互作用； iv）本奖反映了NSF的法定任务，并通过基金会的知识分子优点和更广泛的影响标准，反映了NSF的法定任务，这反映了NSF的法定任务。