The separation of benzene derivatives is energy intensive and laborious as a result of the overlapping physicochemical properties of these isomers. Here, we report on the separation of ortho-disubstituted benzene isomers using cucurbit[7]uril (CB7) aqueous solution with more than 92% selectivity. Thermodynamic and kinetic analysis proves that the ortho-isomer has stronger binding ability and slower decomplexation rate constant than the para- and meta-isomers when hosted by CB7. Optimized host-guest models indicate that the ortho-isomer with the smallest aspect ratio well matches the spherical interior cavity of CB7, resulting in highly stable complexes. Furthermore, laboratory scale-up experiments using commercial xylenes and C8 aromatic fraction of pyrolysis gasoline proved that CB7 is able to separate ortho-xylene (OX) with a remarkable selectivity of up to 83%. We believe that this work accentuates the role of molecular recognition studies using macrocyclic hosts to improve the quality and energy bill of critical industrial separations.

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中文翻译：

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葫芦[7] uril宿主大环化合物实现形状诱导的邻位取代苯异构体的选择性分离

苯衍生物的分离由于这些异构体的重叠物理化学性质而耗费大量能源并且费力。在这里，我们报道了使用葫芦[7] uril（CB7）水溶液以92％以上的选择性分离邻二取代苯异构体的方法。热力学和动力学分析证明，当由CB7托管时，邻位异构体比对位异构体和间位异构体具有更强的结合能力和更慢的分解速率常数。优化的主客体模型表明，长径比最小的邻位异构体与CB7的球形内部空腔完全匹配，从而形成了高度稳定的配合物。此外，使用商业二甲苯和热解汽油的C8芳烃馏分进行的实验室放大实验证明，CB7能够分离邻二甲苯（OX），选择性高达83％。我们认为，这项工作强调了利用大环宿主改善重要工业分离的质量和能耗清单的分子识别研究的作用。

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