新型手性锆基MOFs材料在芳香族氨基酸对映体拆分中的应用

Enantiomers of the same aromatic amino acids generally exhibit different biological activities and practical applications, and most of the synthetic aromatic amino acids are racemic mixtures, thus it is necessary to perform enantiomeric resolution for them. Although some mature methods have been used, and they still remain the problems of high cost, long time consuming and complicated operation steps. Recently some chiral metal-organic frameworks have been used as resolution agents for enantioselective separation of aromatic amino acids, but usually facing with unsatisfactory resolution effect for racemic mixtures, poor stability and poor recyclable performance of metal-organic frameworks. In this context, we intend to construct a series of new chiral Zr-based metal-organic frameworks with excellent stability through the design and regulation of chiral organic ligands, as a result, aromatic amino acid enantiomers will be separated conveniently and efficiently. The interaction between structures of chiral Zr-based metal-organic frameworks and the enantiomers will be studied by regulating the substituents of chiral organic ligands. The relationship between stereoselectivity and the configuration of enantiomers, space volume and the selective adsorption capacity of chiral Zr-based metal-organic frameworks will be investigated. Finally, a general rule will be summarized according to the above-mentioned factors. This project is of great significance for enriching the structural diversity of chiral Zr-based metal-organic frameworks and expanding their current performance research.

同种芳香族氨基酸的对映体通常表现出不同的生物活性与实用价值。目前人工合成的芳香族氨基酸多为外消旋体，因此其拆分是十分必要的。虽然已有一些成熟的拆分方法被使用，但它们面临着成本较高、耗时较长、操作步骤复杂等问题。目前已报道的手性金属-有机框架材料作为手性拆分剂应用到芳香族氨基酸拆分时面临着拆分效果不理想、稳定性及循环性较差等问题。基于此，本项目拟通过对手性有机配体的设计与调控，构建出一系列具有良好稳定性的新型手性锆基金属-有机框架材料，以实现方便且高效地拆分芳香族氨基酸对映体的目的。通过调控有机配体的取代基研究手性锆基金属-有机框架的结构与待拆分物质的相互作用；考察空间立体选择性与待拆分物质构型之间的关系，探索空体积与其选择性吸附量的关系，从而归纳上述因素对芳香族氨基酸拆分能力的影响规律。本项目对丰富手性锆基金属-有机框架材料的结构多样性、拓展其现有的性能研究等均具有十分重要的意义。

锆/铪基金属有机框架（MOFs）材料特别是锆/铪基手性MOFs在对映异构体拆分、不对称催化及碘吸附等领域均有潜在的应用前景。然而上述配合物（尤其是过渡‒锆/铪基异金属有机框架材料）难以结晶，使得此类材料的设计与合成尤为困难。此外，磁开关材料与耐强酸/碱单分子磁体材料的构筑与制备、高核簇合物的组装机制均是磁性材料的研究热点。.基于此，本课题组（1）在溶剂热条件下构筑了10例结构新颖的以[CuxXx]（X = Br、I）和[M6O8]（M = Zr、Hf）为次级构筑单元的Cu‒Zr/Hf基金属有机框架材料，研究了它们的结构并探索了其相关性质。（2）通过后修饰策略获得一系列具有超高碘吸附能力的手性ZIF‒90。碘蒸气吸附实验表明在75℃条件下，后修饰合成的手性ZIF-90饱和吸附量达到6.60 g/g，对碘‒环己烷溶液中碘的吸附量也达到了1.83 g/g，该吸附能力在金属有机框架材料及其衍生物中排在前列。然而，手性的存在与否并不会影响配合物的碘吸附能力。（3）合成了15个多核稀土金属簇{Lnx}和多核过渡‒稀土金属簇{TMxLny}为节点的配合物，并研究了它们的磁学性质及部分簇合物的组装机制。结果表明其中一例配合物表现出溶剂诱导的磁开关效应；构筑了三例耐酸/强碱的4f/3d-4f单分子磁体材料，进一步推动了单分子磁体材料的应用范围。