Advanced Time-Resolved Studies of the O-O Bond Formation Mechanisms: Interplay of the Metal and Ligand Redox Reactivity

O-O 键形成机制的高级时间分辨研究：金属和配体氧化还原反应性的相互作用

• 批准号: 1900476
• 负责人: Yulia Pushkar
• 金额: $ 45万
• 依托单位: Purdue University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-08-01 至 2022-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1900476&HistoricalAwards=false
• 关键词: Advanced; Time; Resolved; Studies; Bond

In this project supported by the Chemical Structure, Dynamic & Mechanism,B Program of the Chemistry Division, Professor Yulia Pushkar of the Department of Physics and Astronomy at Purdue University studies the time-resolved mechanism of dioxygen (O2) formation in artificial photosynthesis. In artificial photosynthesis, solar energy is converted into chemical energy through generation of the clean fuels hydrogen and oxygen, a process which requires rearrangement of chemical bonds. Fundamental understanding of this process is required for the development of new catalysts and devices which are able to mimic natural photosynthesis. The development of artificial photosynthesis and its large-scale implementation can address energy needs of modern society. This research lies at the interface of physics, chemistry and materials science, with results expected to impact diverse fields and contribute to fundamental science, education and national energy security. Planned research and educational activities are designed to increase participation of under-represented students from economically disadvantaged backgrounds, improve experiences of female students in STEM (Science, Technology, Engineering and Mathematics), enhance training of students via integration of research results into curricula and to deliver teaching modules to schools. Research in this project focuses on the complex multi-electron chemical process of artificial photosynthesis. A major project goal is to determine the structure, electronic configurations and dynamics of the critical intermediates involved in water oxidation. In this multi-scale approach, time-resolved techniques monitor the evolution of structure and electronic states in newly designed ruthenium catalysts, with a focus on the key mechanism of oxygen-oxygen bond formation and its dependence on ligand structure. The relationship between molecular structure and catalytic activity is tested by a combination of experiments and quantum-mechanical computational models. Experimental techniques in this study of in situ catalytic water oxidation are synchrotron-based X-ray spectroscopy, including X-ray absorption near edge structure (XANES), extended X-ray absorption fine structure (EXAFS), electron paramagnetic resonance (EPR) and multi-wavelength kinetic resonance Raman spectroscopy. These experimental techniques deliver information on the structure of the intermediates and their electronic configuration as they evolve during the catalytic process.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.

在这个由化学部化学结构、动力学与机制B项目支持的项目中，普渡大学物理与天文学系的Yulia Pushkar教授研究了人工光合作用中分子氧（O2）形成的时间分辨机制。在人工光合作用中，通过产生清洁燃料氢和氧，太阳能被转化为化学能，这一过程需要化学键的重新排列。开发能够模拟自然光合作用的新催化剂和设备需要对这一过程有基本的了解。 人工光合作用的发展及其大规模实施可以满足现代社会的能源需求。这项研究处于物理、化学和材料科学的交叉领域，其结果预计将影响各个领域，并为基础科学、教育和国家能源安全做出贡献。计划的研究和教育活动旨在增加来自经济弱势背景的代表性不足的学生的参与，改善女学生在 STEM（科学、技术、工程和数学）方面的经验，通过将研究成果纳入课程来加强对学生的培训，并向学校提供教学模块。该项目的研究重点是人工光合作用的复杂多电子化学过程。 项目的一个主要目标是确定参与水氧化的关键中间体的结构、电子构型和动力学。 在这种多尺度方法中，时间分辨技术监测新设计的钌催化剂中结构和电子态的演变，重点关注氧-氧键形成的关键机制及其对配体结构的依赖性。通过实验和量子力学计算模型的结合来测试分子结构和催化活性之间的关系。本次原位催化水氧化研究的实验技术是基于同步加速器的X射线光谱，包括X射线吸收近边结构（XANES）、扩展X射线吸收精细结构（EXAFS）、电子顺磁共振（EPR）和多波长动力学共振拉曼光谱。这些实验技术提供了有关中间体结构及其在催化过程中演变的电子构型的信息。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Unraveling the Mechanism of Catalytic Water Oxidation via de Novo Synthesis of Reactive Intermediate

通过活性中间体的从头合成揭示催化水氧化机理

• DOI: 10.1021/jacs.9b10265
• 发表时间: 2019-12
• 期刊: Journal of the American Chemical Society
• 影响因子: 15
• 作者: Ravari, Alireza Karbakhsh;Zhu, Guibo;Ezhov, Roman;Pineda;Page, Allison;Weinschenk, Whitney;Yan, Lifen;Pushkar, Yulia
• 通讯作者: Pushkar, Yulia

A Highly Reactive Chromium(V)–Oxo TAML Cation Radical Complex in Electron Transfer and Oxygen Atom Transfer Reactions

电子转移和氧原子转移反应中的高活性铬(V)-Oxo TAML 阳离子自由基络合物

• DOI: 10.1021/acscatal.1c00079
• 发表时间: 2021-02-18
• 期刊: ACS Catalysis
• 影响因子: 12.9
• 作者: Young Hyun Hong;Yuri Jang;R. Ezhov;M. Seo;Yong‐Min Lee;B. P;ey;ey;Seungwoo Hong;Y. Pushkar;S. Fukuzumi;W. Nam
• 通讯作者: W. Nam

Do multinuclear 3d metal catalysts achieve O–O bond formation via radical coupling or via water nucleophilic attack? WNA leads the way in [Co4O4]n+

多核3d金属催化剂是通过自由基偶联还是通过水的亲核攻击来实现O-O键形成？

• DOI: 10.1016/j.checat.2021.03.013
• 发表时间: 2021-05
• 期刊: Chem Catalysis
• 作者: Ezhov, Roman;Ravari, Alireza Karbakhsh;Bury, Gabriel;Smith, Paul F.;Pushkar, Yulia
• 通讯作者: Pushkar, Yulia

An evolutionarily conserved iron-sulfur cluster underlies redox sensory function of the Chloroplast Sensor Kinase

进化上保守的铁硫簇是叶绿体传感器激酶氧化还原感觉功能的基础

• DOI: 10.1038/s42003-019-0728-4
• 发表时间: 2020-12
• 期刊: Communications Biology
• 影响因子: 5.9
• 作者: Ibrahim, Iskander M.;Wu, Huan;Ezhov, Roman;Kayanja, Gilbert E.;Zakharov, Stanislav D.;Du, Yanyan;Tao, Weiguo Andy;Pushkar, Yulia;Cramer, William A.;Puthiyaveetil, Sujith
• 通讯作者: Puthiyaveetil, Sujith

Atomically Dispersed Iridium on Indium Tin Oxide Efficiently Catalyzes Water Oxidation

氧化铟锡上原子分散的铱有效催化水氧化

• DOI: 10.1021/acscentsci.0c00604
• 发表时间: 2020-07-01
• 期刊: ACS Central Science
• 影响因子: 18.2
• 作者: Dmitry Lebedev;R. Ezhov;Javier Heras;A. Comas‐Vives;N. Kaeffer;M. Willinger;X. Solans;Xing Huang;Y. Pushkar;C. Copéret
• 通讯作者: C. Copéret