RII Track-4: Pulse Radiolysis Studies of H2 Generation by [Cp*Rh] Complexes to Characterize Design Rules for Improved Catalysts

RII Track-4：[Cp*Rh] 配合物产生氢气的脉冲辐射分解研究，以表征改进催化剂的设计规则

• 批准号: 1833087
• 负责人: James Blakemore
• 金额: $ 16.68万
• 依托单位: University of Kansas Center for Research Inc
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-10-01 至 2021-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1833087&HistoricalAwards=false
• 关键词: RII; Track; Pulse; Radiolysis; Studies

Nontechnical DescriptionRenewable energy sources, which provide power without routine emission of pollutants, are being developed rapidly in the United States and elsewhere. However, effective and practical methods for the direct generation of useful chemicals using renewable energy remain elusive. In part, this challenge arises from a lack of detailed and predictive information on the individual steps involved in energy-storing chemical reactions such as hydrogen generation or carbon dioxide conversion. With the support of an EPSCoR Research Fellowship, the PI will conduct research at Brookhaven National Laboratory (BNL), where he and his collaborators will focus on revealing the detailed features of selected energy-storing reactions as they proceed step-by-step. Unique resources available at BNL, including techniques that can monitor reactions in real time as they occur, will be used to conduct studies of active materials developed in the PI?s laboratory at the University of Kansas. Within the framework of this research, the PI and his students will closely collaborate with scientists in the BNL Artificial Photosynthesis group, fostering a strong partnership between institutions that will enable mutually beneficial exchange of knowledge and expertise while also accelerating research progress. More broadly, this effort will further scientific workforce development in Kansas by providing opportunities for enhanced training and dissemination of research findings in local and regional forums. Technical DescriptionThe research effort of this fellowship focuses on experimental study of mechanisms of proton and electron management in reductive molecular catalysis. Proton/electron management is important in artificial photosynthetic systems that can be used to generate energy-dense chemicals and fuels; in such systems, water serves as a sacrificial reagent to provide reducing equivalents to catalysts that mediate formation of reduced products. A group of [Cp*Rh]-based molecular catalysts (Cp* = pentamethylcyclopentadienyl; Rh = rhodium) developed in the PI?s laboratory are the target of the studies in this project, as they are highly active for catalysis, recyclable, and built from commonly available components. However, unexpected metal- and ligand-centered protonation events have recently been implicated in the activity of these compounds, motivating detailed studies aimed at revealing the features of their structure and bonding that favor efficient catalysis. On-site experimental work at BNL will focus on pulse radiolysis and time-resolved UV-visible and infrared spectroscopic studies in order to generate and observe the transient intermediates involved in catalysis, with the goal of elucidating the roles of specific protonation sites, metal hydride species, and ancillary redox-active ligands. Complexes that feature a variety of ligand environments will be studied, including model compounds that complement the active catalysts. The outcomes of this research include fundamental knowledge for rational design of improved molecular catalysts, particularly systems with ligand environments built upon cyclopentadienyl-type ligands that may function as unconventional proton relays. Notably, the design rules developed here could be broadly useful, as cyclopentadienyl ligands are ubiquitous in organometallic chemistry and catalysis, and are commonly used in industry.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.

非技术性描述可再生能源，它提供电力而不排放常规污染物，正在美国和其他地方迅速发展。然而，使用可再生能源直接生产有用化学品的有效和实用方法仍然难以捉摸。在某种程度上，这一挑战是由于缺乏关于能量储存化学反应（如制氢或二氧化碳转化）中各个步骤的详细和预测性信息。在EPSCoR研究奖学金的支持下，PI将在布鲁克海文国家实验室（BNL）进行研究，在那里他和他的合作者将专注于揭示选定的储能反应的详细特征，因为它们一步一步地进行。在BNL可用的独特资源，包括技术，可以监测反应在真实的时间，因为他们发生，将被用来进行研究的活性材料开发的PI？他在堪萨斯大学的实验室工作。在这项研究的框架内，PI和他的学生将与BNL人工光合作用组的科学家密切合作，促进机构之间的强有力的伙伴关系，这将使知识和专业知识的互利交流，同时也加快研究进展。更广泛地说，这一努力将通过在地方和区域论坛上提供加强培训和传播研究成果的机会，进一步促进堪萨斯的科学劳动力发展。 本研究项目主要研究还原性分子催化中质子和电子管理机制的实验研究。质子/电子管理在可用于产生能量密集型化学品和燃料的人工光合系统中是重要的;在这样的系统中，水充当牺牲试剂以向介导还原产物形成的催化剂提供还原当量。一组[Cp*Rh]为基础的分子催化剂（Cp* =五甲基溴; Rh =铑）开发的PI？的实验室是该项目研究的目标，因为它们具有高度的催化活性，可回收利用，并由常见的组件构建。然而，意想不到的金属和配体为中心的质子化事件最近被牵连在这些化合物的活性，激发详细的研究，旨在揭示其结构和键合的特点，有利于有效的催化。BNL的现场实验工作将集中在脉冲辐解和时间分辨紫外可见和红外光谱研究，以产生和观察参与催化的瞬态中间体，目的是阐明特定质子化位点，金属氢化物物种和辅助氧化还原活性配体的作用。将研究具有各种配体环境的络合物，包括补充活性催化剂的模型化合物。这项研究的成果包括改进的分子催化剂的合理设计的基础知识，特别是系统与配体环境的环戊二烯基型配位体，可作为非常规的质子中继建立。值得注意的是，这里开发的设计规则可能是广泛有用的，因为双金属配体在有机金属化学和催化中无处不在，并且通常用于工业中。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影响审查标准进行评估来支持。

项目成果

Chemical and Electrochemical Properties of [Cp*Rh] Complexes Supported by a Hybrid Phosphine-Imine Ligand

• DOI: 10.1021/acs.organomet.8b00551
• 发表时间: 2019-03-25
• 期刊: ORGANOMETALLICS
• 影响因子: 2.8
• 作者: Hopkins, Julie A.;Lionetti, Davide;Blakemore, James D.
• 通讯作者: Blakemore, James D.

Structural and chemical properties of half-sandwich rhodium complexes supported by the bis(2-pyridyl)methane ligand

双(2-吡啶基)甲烷配体负载的半夹心铑配合物的结构和化学性质

• DOI: 10.1039/c9dt01821b
• 发表时间: 2019
• 期刊: Dalton Transactions
• 影响因子: 4
• 作者: Lionetti, Davide;Day, Victor W.;Blakemore, James D.
• 通讯作者: Blakemore, James D.

Electrochemical Kinetic Study of [Cp*Rh] Complexes Supported by Bis(2-pyridyl)methane Ligands

双(2-吡啶基)甲烷配体支持的[Cp*Rh]配合物的电化学动力学研究

• DOI: 10.1021/acs.organomet.0c00747
• 发表时间: 2021
• 期刊: Organometallics
• 影响因子: 2.8
• 作者: Hopkins Leseberg, Julie A.;Lionetti, Davide;Day, Victor W.;Blakemore, James D.
• 通讯作者: Blakemore, James D.

Incorporation of [Cp*Rh] and [Cp*Ir] Species into Heterobimetallic Complexes via Protonolysis Reactivity and Dioximato Chelation

通过质子分解反应性和二肟螯合将 [Cp*Rh] 和 [Cp*Ir] 物质掺入异双金属配合物中

• DOI: 10.1021/acs.inorgchem.1c01362
• 发表时间: 2021
• 期刊: Inorganic Chemistry
• 影响因子: 4.6
• 作者: Kumar, Amit;Comadoll, Chelsea G.;King, Daniel S.;Oliver, Allen G.;Day, Victor W.;Blakemore, James D.
• 通讯作者: Blakemore, James D.

4,5-Diazafluorene and 9,9’-Dimethyl-4,5-Diazafluorene as Ligands Supporting Redox-Active Mn and Ru Complexes

4,5-二氮杂芴和 9,9-二甲基-4,5-二氮杂芴作为支持氧化还原活性锰和钌配合物的配体

• DOI: 10.3390/molecules25143189
• 发表时间: 2020
• 期刊: Molecules
• 影响因子: 4.6
• 作者: Henke, Wade C.;Hopkins, Julie A.;Anderson, Micah L.;Stiel, Jonah P.;Day, Victor W.;Blakemore, James D.
• 通讯作者: Blakemore, James D.