Visualizing Ultrafast Chemical Reaction Dynamics

超快化学反应动力学可视化

• 批准号: 2154157
• 负责人: Roseanne Sension
• 金额: $ 52.5万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-01 至 2025-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2154157&HistoricalAwards=false
• 关键词: Visualizing; Ultrafast; Chemical; Reaction; Dynamics

With support from the Chemical Structure, Dynamics, and Mechanisms-A (CSDM-A) program in the Division of Chemistry, Professors Roseanne Sension and James Penner-Hahn of the University of Michigan are combining advanced visible and x-ray laser methods to watch the movement of atoms and electrons during the making and breaking of chemical bonds. Chemical reactions are controlled by the coupled motions of atoms and electrons on time scales measured in trillionths of a second or shorter. No ordinary camera can capture this movement. Professors Sension and Penner-Hahn and their students will use very short x-ray pulses to image the coupled motions of atoms and electrons in photochemical reactions, focusing on one element at a time. Their discoveries could lead to the design of more efficient chemicals used in applications ranging from photo-selective drug delivery to industrially important photocatalysts. This project will also contribute to education and human resource development by training a diverse group of graduate and undergraduate students to work at the interface of x-ray physics, optics, chemical dynamics, and inorganic chemistry. Chemical reactions involve changes in atomic arrangement, electron distribution, and bonding. Professors Sension and Penner-Hahn combine strengths in ultrafast spectroscopy and x-ray spectroscopy to visualize, describe, and control these dynamics. By using light to initiate reactions, the molecular behavior can be synchronized, allowing studies on time scales ranging from attoseconds, for electronic rearrangements, to femtoseconds and picoseconds for atomic motion. Polarization and time-resolved x-ray spectroscopies will provide an element specific view of chemical reaction dynamics, complementing and extending the view provided by optical and vibrational spectroscopies. The results could challenge conventional thinking, identify new phenomena, and overturn previous models. In this project Professors Sension and Penner-Hahn and their students will focus on the ultrafast coherent dynamics of transition metal containing systems, including organocobalt complexes, that drive both biologically relevant transformations and technologically important molecular conversions, as well as the light-driven conformational changes in polyenes that underlie processes ranging from vision to molecular motors. Ultrafast x-ray spectroscopies are applicable to a broad range of systems active in transport, energy harvesting, energy storage and biological systems. The broader impacts of this work include the development of methods that enable a wider use of time-resolved x-ray spectroscopies in the chemical community.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.

在化学结构，动力学和机制-A（CSDM-A）方案的支持下，密歇根大学的Roseanne Sension教授和James Penner-Hahn将高级可见光和X射线激光方法结合在一起，以观察在化学键制造和破裂过程中原子和电子的运动。化学反应由原子和电子的耦合动作控制在第二秒或较短的数百万分之一中测得的时间尺度。没有普通的相机可以捕捉这一动作。教授Sension和Penner-Hahn及其学生将使用非常短的X射线脉冲来对光化学反应中原子和电子的耦合动作进行图像，一次重点是一个元素。他们的发现可能导致设计用于从光选择性药物到工业重要的光催化剂的应用中使用的更有效的化学物质。该项目还将通过培训各种各样的研究生和本科生在X射线物理，光学，化学动力学和无机化学的界面上工作，从而为教育和人力资源开发做出贡献。 化学反应涉及原子排列，电子分布和键合的变化。教授Sension和Penner-Hahn在超快光谱和X射线光谱中结合了强度，以可视化，描述和控制这些动力学。通过使用光启动反应，可以同步分子行为，从而可以按时间尺度进行研究，从attseconds，电子重排，到巨秒和picseconds，以进行原子运动。极化和时间分辨X射线光谱镜将提供化学反应动力学的特定元素视图，并补充和扩展由光学和振动光谱镜提供的视图。结果可能会挑战常规思维，确定新现象并推翻以前的模型。 在这个项目中，教授Sension和Penner-Hahn及其学生将专注于含有过渡金属系统的超快相干动力，包括Organocobalt Complexs，这些动力既可以驱动生物学上相关的转换和技术重要的分子转换，又是光驱动的构象变化在从视觉到分子电动机的过程的基础的多元中。 Ultrafast X射线光谱镜适用于活跃于运输，能源收集，能源存储和生物系统的广泛系统。这项工作的更广泛影响包括开发化学界可以更广泛利用时间分辨X射线光谱的方法。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子和智力优点和评估的支持。更广泛的影响审查标准。

项目成果

Watching Excited State Dynamics with Optical and X-ray Probes: The Excited State Dynamics of Aquocobalamin and Hydroxocobalamin

使用光学和 X 射线探针观察激发态动力学：水钴胺和羟钴胺的激发态动力学

• DOI: 10.1021/jacs.3c04099
• 发表时间: 2023
• 期刊: Journal of the American Chemical Society
• 影响因子: 15
• 作者: Sension, Roseanne J.;McClain, Taylor P.;Lamb, Ryan M.;Alonso-Mori, Roberto;Lima, Frederico Alves;Ardana-Lamas, Fernando;Biednov, Mykola;Chollet, Matthieu;Chung, Taewon;Deb, Aniruddha
• 通讯作者: Deb, Aniruddha