Artificial Enzymes: Development of Biomimetic Catalysts in Metal-Organic Frameworks

人工酶：金属有机框架仿生催化剂的开发

• 批准号: 9397216
• 负责人: Christine N Morrison
• 金额: $ 5.63万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-12-01 至 2020-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9397216
• 关键词: Acetylene; Acids; Ammonia; Anabolism; Binding; Biological Markers; Biomimetic Materials; Biomimetics; Catalysis; Catalytic Domain; Complex; Development; Electrons; Enzymes; Ethylenes; Health; Human; Hydrogen; Hydrogenase; Industrialization; Ligands; Metalloproteins; Metals; Methods; Modeling; Natural Gas; Nitrogenase; Outcome; Photosensitization; Photosensitizing Agents; Planet Earth; Production; Proteins; Protons; Reaction; Reducing Agents; Reporting; Research; Sampling; Scheme; Site; Technology; Testing; Work; biological systems; biomaterial compatibility; catalyst; design; insight; molecular hydrogen; oxidation; small molecule

PROJECT SUMMARY/ABSTRACT This research aims to create new metal-organic frameworks with FeS clusters modeled from metalloproteins. Using earth-abundant, biocompatible metals such as Fe in the biomimetic catalysts will enhance health by contributing to the development of materials that may be used on human samples for applications such as sensing biological markers. More specifically, successful synthesis of the proposed materials will allow for the catalysis of more complex and wide-ranging reactions in artificial enzymes. Two related projects are proposed. First, a biomimetic MOF containing [2Fe:2S] clusters and photosensitizers that can efficiently catalyzes the reduction of protons to molecular hydrogen will be constructed. A few examples of [2Fe:2S]-MOFs are reported; however, they have not been optimized for efficient catalysis. Using a recently presented MOF called PCN-700, a linker containing a [2Fe:2S] cluster and another containing a photosensitizer will be postsynthetically installed in the PCN-700 framework to yield a catalytic MOF. These [2Fe:2S]-MOFs can then be easily tuned for catalytic efficiency by installing a third linker that is functionalized to control polar contacts within the MOF. Second, MOFs containing [4Fe:4S] clusters will be synthesized and assessed for catalytic activity. Successful inclusion of [4Fe:4S] clusters in a MOF would expand the catalytic and/or biomimetic potential of MOFs by utilizing the additional available oxidation states afforded by the four Fe sites compared to smaller FeS clusters. For example, more complex reactions could be carried out, such as those requiring four or more electrons. Also, since [4Fe:4S] clusters can bind reaction intermediates (which has not been demonstrated with [2Fe:2S] clusters in a protein), the [4Fe:4S]-MOFs may be used to study reaction intermediates that have not been successfully characterized using the biological system or small molecules. Two approaches are proposed for synthesizing [4Fe:4S]-MOFs. First, free [4Fe:4S] clusters will be synthesized with -SCH3 groups on each Fe. These SCH3 ligands will be exchanged with the bifunctional linker 4,4’-biphenyldithiol to yield a framework, in the presence of reductant and acid. The second synthetic approach involves assembling the FeS clusters and the framework simultaneously by using 4,4’-biphenyldithiol instead of HSCH3 in the scheme originally designed for synthesizing free [4Fe:4S] clusters. Overall, the results of this work will advance the field of biomimetic catalysts using FeS clusters. The proposed [2Fe:2S]-MOFs will be optimized for catalytic activity, and the proposed [4Fe:4S]-MOFs would be the first of their kind, thereby introducing a new class of biomimetic catalysts.

项目概要/摘要 这项研究旨在创建新的金属有机框架，其模型为 FeS 簇 金属蛋白。在仿生催化剂中使用地球上丰富的生物相容性金属（例如铁）将 通过促进可用于人体样本的材料的开发来增强健康 应用，例如传感生物标记。更具体地说，成功合成了所提出的 材料将允许在人造酶中催化更复杂和更广泛的反应。 提出了两个相关项目。首先，包含[2Fe:2S]簇的仿生MOF和 能够有效催化质子还原为分子氢的光敏剂 建造的。报道了一些 [2Fe:2S]-MOF 的例子；然而，它们还没有针对以下方面进行优化： 高效催化。使用最近提出的称为 PCN-700 的 MOF，它是一个包含 [2Fe:2S] 簇的链接器和 另一个包含光敏剂的物质将在合成后安装在 PCN-700 框架中，以产生 催化 MOF。然后可以通过安装第三个连接体轻松调整这些 [2Fe:2S]-MOF 的催化效率 它被功能化以控制 MOF 内的极性接触。 其次，将合成含有[4Fe:4S]簇的MOF并评估其催化活性。 MOF 中成功包含 [4Fe:4S] 簇将扩大其催化和/或仿生潜力 与较小的 MOF 相比，MOF 利用四个 Fe 位点提供的额外可用氧化态 FeS簇。例如，可以进行更复杂的反应，例如需要四个或更多的反应 电子。此外，由于 [4Fe:4S] 簇可以结合反应中间体（尚未用 [2Fe:2S] 簇在蛋白质中），[4Fe:4S]-MOF 可用于研究未发生反应的反应中间体 使用生物系统或小分子已成功表征。提出了两种方法 用于合成[4Fe:4S]-MOF。首先，自由的[4Fe:4S]簇将与每个簇上的-SCH3基团合成 铁。这些 SCH3 配体将与双功能接头 4,4'-联苯二硫醇交换以产生框架， 在还原剂和酸存在下。第二种合成方法涉及组装 FeS 团簇 和框架同时使用4,4'-联苯二硫醇代替原方案中的HSCH3 设计用于合成游离的[4Fe:4S]簇。 总的来说，这项工作的结果将推动使用 FeS 团簇的仿生催化剂领域的发展。这 提议的 [2Fe:2S]-MOF 将针对催化活性进行优化，提议的 [4Fe:4S]-MOF 将是 这是同类产品中的首创，从而引入了一类新型仿生催化剂。