Synthesis of Noble Metal-oxo Cluster-based Metal-Organic Frameworks and their Use in Heterogeneous Catalysis and Magnetism

本项目旨在系统设计、合成和表征一系列全新的基于多氧贵金属酸盐（PONM）的金属有机骨架（mof），并研究其催化和磁性能。不同形状、大小和成分的聚氧酸盐（pop）和聚氧酸盐（poa）将被用于构建贵金属和混合贵金属基PONM-MOFs。这种框架材料的稳定性和组成将通过适当修改有机连接剂或采用双二次构建单元（SBU）策略来调整，其中POP/POA SBU将与其他类型的SBU连接，例如传统的pom、贵金属配合物或单金属离子。该项目预计将产生一个基于ponm - mof的非均相催化剂库，具有单或双催化中心，可用于有机氧化，还原和C-C偶联反应。所获得的ponm - mof也可以用作牺牲模板来合成贵金属或混合贵金属基nanoparticles@porous-carbon复合材料，这些复合材料将作为光催化和电催化反应的催化剂进行测试。由ponm - mof形成的贵金属基纳米颗粒具有很高的吸引力，因为纳米颗粒的组成和尺寸可以通过简单地使用不同形状、尺寸和组成的ponm作为SBUs来调节。我们还打算利用以镧系元素为中心的POP作为SBUs来分离镧系元素-POP- mof，并将它们作为分子自旋量子比特进行研究，因为POP腔内的单个镧系离子表现出高度对称的配位环境（LnPd12纳米立方体中的8位配位或LnPd15纳米星中的10位配位五角形）。ln - pop - mof在刚性框架中具有良好的定向性，并且可以通过增加/减少有机连接体的长度或使用柔性有机连接体来微调单个自旋量子比特之间的相互作用。最近对POP-MOFs的合成、结构和催化进行了原理论证(J. Am.；化学。Soc. 2019, 141, 3385−3389)。

This project aims at the systematic design, synthesis and characterization of a series of fundamentally novel polyoxo-noble-metalate (PONM)-based metal-organic frameworks (MOFs) and the investigation of their catalytic and magnetic properties. The entire class of discrete polyoxopalladates (POPs) and polyoxoaurates (POAs) of different shape, size and composition will be utilized to construct noble-metal and mixed noble-metal-based PONM-MOFs. The stability and composition of such framework materials will be tuned by suitable modification of the organic linkers, or by employing a dual secondary-building-unit (SBU) strategy, wherein the POP/POA SBUs will be linked to other types of SBUs such as conventional POMs, noble-metal complexes or single metal-ions. This project is expected to result in a library of PONM-MOF-based heterogeneous catalysts with either single or dual catalytic centers, which will be utilized as catalysts for organic oxidation, reduction, and C-C coupling reactions. The obtained PONM-MOFs can also be used as sacrificial templates to synthesize noble-metal- or mixed-noble-metal-based nanoparticles@porous-carbon composites, which will be tested as catalysts for photo- and electrocatalytic reactions. The formation of noble-metal-based nanoparticles from PONM-MOFs is highly attractive, because the composition and size of the nanoparticles can be tuned by simply using PONMs of different shape, size and composition as SBUs. We also aim to utilize lanthanide-centered POPs as SBUs to isolate Ln-POP-MOFs and to study them as molecular spin qubits, because the individual lanthanide ions inside the POP cavities exhibit highly symmetrical coordination environments (8-coordinated cubic in the LnPd12 nanocube or 10-coordinated pentagonal-prismatic in the LnPd15 nanostar). The Ln-POPs are well-oriented in the rigid framework of the Ln-POP-MOFs and the interactions of the individual spin qubits with each other can be fine-tuned by increasing/decreasing the length of the organic linkers or by using flexible organic linkers. The proof of principle for the synthesis, structure and catalysis of POP-MOFs was demonstrated recently (J. Am. Chem. Soc. 2019, 141, 3385−3389).