Understanding the structure–property relationship is conducive to the rational design and synthesis of porous MOFs with better performance. In this work, we constructed three isoreticular MOFs derived from quinoline-functionalized bent diisophthalate ligands as a platform to investigate the positional effect of nitrogen functional sites on the structural stabilities and gas adsorption properties of the resulting MOFs. N₂ adsorption experiments performed at 77 K revealed that the three MOF compounds exhibited different stabilities against the framework desolvation, which we think is attributed to different accessibility degrees of nitrogen functional sites leading to different interactions between the frameworks and activated solvent molecules. In addition, as a consequence of the incorporation of nitrogen functional sites into the framework, the most stable MOF ZJNU-84 outperformed its parent compound ZJNU-71 in terms of C₂H₂ and CO₂ uptake capacities and C₂H₂/CH₄ and CO₂/CH₄ adsorption selectivities, indicating its promising potential for the selective separation of C₂H₂ and CO₂ from CH₄. However, the enhancement is not as remarkable as expected due to a low degree of accessibility of nitrogen functional sites in the framework.

中文翻译：

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源自氮官能化的二间苯二甲酸酯配体的三个等规MOF：探索氮官能位对结构稳定性和选择性C ₂ H ₂ / CH ₄和CO ₂ / CH ₄吸附特性的位置影响†

理解结构-性质之间的关系有助于合理设计和合成具有更好性能的多孔MOF。在这项工作中，我们构造了三个由喹啉官能化的弯曲二间苯二甲酸酯配体衍生的等规网状MOF，以此为平台来研究氮官能位对所得MOF的结构稳定性和气体吸附性能的位置影响。N ₂在77 K下进行的吸附实验表明，三种MOF化合物对骨架去溶剂化表现出不同的稳定性，我们认为这是由于氮官能位的可及度不同，导致骨架与活化的溶剂分子之间的相互作用不同。此外，由于将氮官能团引入了骨架，因此最稳定的MOF ZJNU-84在C ₂ H ₂和CO ₂吸收能力以及C ₂ H ₂ / CH方面优于其母体化合物ZJNU-71。₄和CO ₂ / CH ₄吸附选择性，表明其从CH ₄选择性分离C ₂ H ₂和CO _2的潜在潜力。但是，由于框架中氮官能位的可及性较低，因此增强效果不如预期的显着。