Exploring secondary interactions in Metal-Organic Frameworks

探索金属有机框架中的次级相互作用

• 批准号: RGPIN-2022-04914
• 负责人: Katz, Michael
• 金额: $ 3.5万
• 依托单位: Memorial University of Newfoundland
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=747938
• 关键词: Exploring; secondary; interactions; Metal; Organic

Metal-organic frameworks (MOFs) are porous materials formed from inorganic cations, dimers, or clusters (nodes), and organic bridging ligands (linkers). Each pore of the MOF can be viewed as a reaction chamber built for an application. With judicious choice of node and linker, the pore aperture, size, and functional group decorating the pore can be tuned. Barring defects/surface effects, the porous and crystalline nature of MOFs results in nodes and linkers existing in isolated and well-defined environments that can be accessed by guest molecules. For adsorption/catalysis, building an active site into a MOF removes deactivation pathways such as aggregation. Researchers have explored this by building MOFs with linkers/nodes that have strongly adsorbing/reactive sites. Secondary interactions are interactions that improve or modify the existing adsorption/catalysis process. They can interact with the guest, the catalyst, or modify the sterics/electronics around the active site. These secondary interactions can improve adsorption, transition state stabilization, or desorption. Despite this, introducing secondary sites into MOFs has been poorly explored. The proposal will explore secondary interactions in MOFs using three linker systems. Each system enables us to study a different aspect of secondary interactions. Linker System A is based on a known porphyrin linker. The linker contains two locations on the porphyrin where secondary interactions will be incorporated in such a way as to participate with chemistry around the metal core of the porphyrin. This will give us the opportunity to explore secondary interactions early on. Linker System B is a new porphyrin linker where the four meso carbons will be modified with secondary interaction groups. With the linker, the active site can be congested to examine sterics. Additionally, complimentary secondary interactions (e.g., donor and acceptor) will be explored. Linker System C is a phthalocyanine linker. These linkers are poorly explored due to the symmetry of the phthalocyanine and the associated isomers. We have identified a method to prepare a phthalocyanine linker that doesn't have the symmetry limitation while also enabling up to eight locations to introduce secondary interactions. Two types of secondary interactions will be explored. Rigid secondary interactions force functional groups to remain in the same environment around the active site. Flexible secondary interactions are dynamic and functional groups can enter/exit the active site. The new MOFs will be explored using single component gas adsorption to determine thermodynamics, and single/multicomponent breakthrough experiments to study kinetics and competitive binding. We will couple this with in-situ IR experiments to determine the mode of action of secondary interactions. We will utilize this information to explore applications in hemoglobin mimics, methane to methanol conversion, chiral catalysis, and explore singlet oxygen chemistry.

金属-有机骨架（M0 F）是由无机阳离子、二聚体或簇（节点）和有机桥接配体（连接体）形成的多孔材料。M0 F的每个孔可以被视为为应用而构建的反应室。通过明智地选择节点和连接体，可以调节孔径、尺寸和修饰孔的官能团。除了缺陷/表面效应之外，MOF的多孔和结晶性质导致存在于可被客体分子访问的隔离和明确定义的环境中的节点和连接体。对于吸附/催化，将活性位点构建到MOF中去除了失活途径，例如聚集。研究人员通过构建具有强吸附/反应位点的连接体/节点的MOF来探索这一点。次级相互作用是改善或改变现有吸附/催化过程的相互作用。它们可以与客体、催化剂相互作用，或者改变活性位点周围的空间/电子学。这些次级相互作用可以改善吸附、过渡态稳定或解吸。尽管如此，在MOF中引入次级位点的探索很少。该提案将探索使用三个连接系统的MOFs中的次级相互作用。每个系统都使我们能够研究次级相互作用的不同方面。接头体系A基于已知的卟啉接头。连接体在卟啉上含有两个位置，其中二级相互作用将以参与卟啉金属核周围的化学的方式并入。这将使我们有机会探索次级相互作用的早期。连接体系统B是一种新的卟啉连接体，其中四个中位碳将被次级相互作用基团修饰。使用接头，活性位点可以被拥挤以检查空间位阻。此外，互补的次级交互（例如，供体和受体）将被探索。接头体系C是酞菁接头。由于酞菁和相关异构体的对称性，这些连接体的研究很少。我们已经确定了一种制备酞菁连接体的方法，该酞菁连接体不具有对称性限制，同时还能够在多达八个位置引入次级相互作用。将探索两种类型的二次交互。刚性次级相互作用迫使官能团保持在活性位点周围的相同环境中。灵活的二次交互是动态的，功能组可以进入/退出活动站点。新的MOFs将使用单组分气体吸附来确定热力学，以及单/多组分突破实验来研究动力学和竞争结合。我们将结合原位红外实验来确定次级相互作用的作用模式。我们将利用这些信息来探索血红蛋白模拟，甲烷到甲醇的转化，手性催化，并探索单线态氧化学的应用。