Macrocycles have found uses in guest capture, sensing and porous materials, motivating the development of new methods for their synthesis. Here we report the construction of two types of barrel-shaped macrocyclic assemblies, with trigonal antiprismatic Fe^II₆L₆ and square antiprismatic Fe^II₈L₈ architectures, from Fe^II and boron-containing tritopic ligands. Two factors, the steric hindrance of ligands and the preferred coordination angles at different vertices, were observed to regulate the dihedral angles between adjacent ligands, leading to the formation of the structures observed. The effects of ligand steric hindrance led to the formation of a Fe^II₆L₆ trigonal antiprism, which efficiently encapsulated persistent environmental pollutant perfluorosulfonate anions. In contrast with the iminopyridine chelating groups of the Fe^II₆L₆ structure, the incorporation of azopyridine moieties coordinated to the Fe^II centres not only increased the vertex opening angle, resulting in the construction of a Fe^II₈L₈ square antiprism, but also enabled the redox-driven reversible disassembly of this structure. The design strategies that have enabled the construction of these antiprismatic macrocycles may provide insight into the design principles governing the formation of more complex functional assemblies.

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中文翻译：

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对配体间二面体和展开的空间控制导致 FeII6L6 和 FeII8L8 反棱镜的形成

大环化合物已在客体捕获、传感和多孔材料中得到应用，推动了其合成新方法的开发。在这里，我们报道了由 Fe ^II和含硼三位配体构建的两种类型的桶状大环组装体，具有三角反棱柱 Fe ^II ₆ L ₆和方形反棱柱 Fe ^II ₈ L ₈结构。观察到两个因素，配体的空间位阻和不同顶点的优选配位角，调节相邻配体之间的二面角，导致观察到的结构的形成。配体空间位阻的作用导致形成Fe ^II ₆ L ₆三角反棱镜，它有效地封装了持久性环境污染物全氟磺酸根阴离子。与 Fe ^II ₆ L ₆结构的亚氨基吡啶螯合基团相反，与 Fe ^II中心配位的偶氮吡啶部分的掺入不仅增加了顶开角，导致构建了 Fe ^II ₈ L ₈方形反棱镜，而且还实现了该结构的氧化还原驱动的可逆拆卸。能够构建这些反棱柱大环的设计策略可以提供对控制更复杂的功能组件形成的设计原则的深入了解。

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