Synthetic Models of the Oxygen Evolving Complex of Photosystem II

光系统II放氧复合物的合成模型

• 批准号: 1905320
• 负责人: Theodor Agapie
• 金额: $ 36万
• 依托单位: California Institute of Technology
• 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: 2019-07-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1905320&HistoricalAwards=false
• 关键词: Synthetic; Models; Oxygen; Evolving; Complex

With this award, the Chemistry of Life Processes Program in the Chemistry Division is funding Dr. Agapie to study the way in which the structure of clusters of manganese and calcium ions affect their ability to convert water into molecular oxygen. This research can provide information about the chemical reactions that underscores photosynthesis in plants, the process by which the plants capture solar energy and use it to transform carbon dioxide and water molecules in other, more complex molecules like sugars needed for their survival. The conversion of water to oxygen is catalyzed in plants by a manganese and calcium cluster and Dr. Agapie synthesizes analogues in his lab. Dr. Agapie and his team study the reactions of these artificial analogues in comparison with the natural systems. The results of his research provide information on how to build catalysts from different metal ions that may be used in artificial photosynthesis. These studies allow graduate students to acquire expertise in a range of synthetic and analytical characterization techniques for complex coordination compounds and to prepare for 21st century STEM careers. Dr. Agapie's research lab performs structure-reactivity studies of a series of manganese cluster models of the Oxygen Evolving Complex (OEC). OEC is responsible for converting water into oxygen in Photosystem II (PSII), a protein complex that captures photons from sunlight and uses them to create electrons needed in chemical reactions in plants. The conversion of water to dioxygen is important for energy storage and conversion in artificial photosynthesis. The transformation of water into oxygen generates reducing equivalents used to transform low-energy precursors, such as carbon dioxide into energy-rich ones, such as sugars (in biological systems) or liquid hydrocarbons (an attractive target in artificial systems). Despite significant advances in the study of PSII, the atomic level mechanism of water oxidation continues to be debated. Supported by preliminary results that demonstrate that structural motifs relevant to the OEC and desired O-O bond formation chemistry can be accessed, mechanistic and reactivity studies are performed. Cluster models of the OEC displaying the dangler metal motif are prepared. In these clusters, the metal centers are site differentiated, which allows for systematic evaluation of the effect of remote metals on their properties. The effect of the cluster geometry, composition, redox state and spin state, on reactivity and spectroscopy are addressed.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.

有了这个奖项，化学部的生命过程化学项目资助Agapie博士研究锰和钙离子簇的结构如何影响它们将水转化为分子氧的能力。 这项研究可以提供有关强调植物光合作用的化学反应的信息，植物捕获太阳能并利用它将二氧化碳和水分子转化为其他更复杂的分子，如生存所需的糖。 水转化为氧气在植物中被锰和钙簇催化，Agapie博士在他的实验室合成了类似物。 Agapie博士和他的团队研究了这些人工类似物与自然系统的反应。 他的研究结果提供了如何从不同的金属离子中构建催化剂的信息，这些催化剂可用于人工光合作用。 这些研究使研究生能够获得复杂配位化合物的一系列合成和分析表征技术的专业知识，并为21世纪的STEM职业做好准备。 Agapie博士的研究实验室对析氧复合物（OEC）的一系列锰簇模型进行结构反应性研究。 OEC负责将水转化为光系统II（PSII）中的氧气，PSII是一种蛋白质复合物，可以从阳光中捕获光子并利用它们来产生植物化学反应所需的电子。在人工光合作用中，水转化为分子氧对于能量的储存和转化是重要的。水转化为氧气会产生还原当量，用于将低能量前体（例如二氧化碳）转化为富含能量的前体，例如糖（在生物系统中）或液体碳氢化合物（人工系统中有吸引力的目标）。尽管PSII的研究取得了重大进展，但水氧化的原子水平机制仍存在争议。初步结果表明，相关的OEC和所需的O-O键形成化学的结构基序可以访问的支持下，进行机理和反应性研究。簇模型的OEC显示悬垂金属图案的准备。在这些集群中，金属中心的网站分化，这使得远程金属对其性能的影响进行系统的评估。该奖项反映了NSF的法定使命，并已被认为是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的支持。

项目成果

Remote Ligand Modifications Tune Electronic Distribution and Reactivity in Site-Differentiated, High-Spin Iron Clusters: Flipping Scaling Relationships

• DOI: 10.1021/acs.inorgchem.9b02470
• 发表时间: 2019-12-02
• 期刊: INORGANIC CHEMISTRY
• 影响因子: 4.6
• 作者: Arnett, Charles H.;Kaiser, Jens T.;Agapie, Theodor
• 通讯作者: Agapie, Theodor

Mixed-Valent Diiron μ-Carbyne, μ-Hydride Complexes: Implications for Nitrogenase

• DOI: 10.1021/jacs.0c05920
• 发表时间: 2020-11-04
• 期刊: JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
• 影响因子: 15
• 作者: Arnett, Charles H.;Bogacz, Isabel;Agapie, Theodor
• 通讯作者: Agapie, Theodor

Activation of an Open Shell, Carbyne-Bridged Diiron Complex Toward Binding of Dinitrogen

• DOI: 10.1021/jacs.0c01896
• 发表时间: 2020-06-03
• 期刊: JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
• 影响因子: 15
• 作者: Arnett, Charles H.;Agapie, Theodor
• 通讯作者: Agapie, Theodor