Intricacy anchored by uranium Metal-organic frameworks generally have one level of assembly complexity: Organic linkers join inorganic nodes in a repeating lattice. Li et al. created a structure composed of cuboctahedra, assembled from uranium cations and organic linkers, that shared triangular faces to form prisms. These structures formed cages, which in turn joined to make tetrahedra that assembled with a diamond-lattice topology. This hierarchical open structure generated a huge unit cell with more than 800 nodes and linkers, containing internal cavities with diameters of 5 and 6 nm. Science, this issue p. 624 An extremely low-density, hierarchical metal-organic framework is anchored by oxygen-coordinated uranium cations. Bottom-up construction of highly intricate structures from simple building blocks remains one of the most difficult challenges in chemistry. We report a structurally complex, mesoporous uranium-based metal-organic framework (MOF) made from simple starting components. The structure comprises 10 uranium nodes and seven tricarboxylate ligands (both crystallographically nonequivalent), resulting in a 173.3-angstrom cubic unit cell enclosing 816 uranium nodes and 816 organic linkers—the largest unit cell found to date for any nonbiological material. The cuboctahedra organize into pentagonal and hexagonal prismatic secondary structures, which then form tetrahedral and diamond quaternary topologies with unprecedented complexity. This packing results in the formation of colossal icosidodecahedral and rectified hexakaidecahedral cavities with internal diameters of 5.0 nanometers and 6.2 nanometers, respectively—ultimately giving rise to the lowest-density MOF reported to date.

中文翻译：

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自下而上构建多孔铀有机晶体中的超结构

由铀锚定的复杂性 金属-有机框架通常具有一层组装复杂性：有机连接器在重复晶格中连接无机节点。李等人。创造了一种由立方八面体组成的结构，由铀阳离子和有机连接体组装而成，共享三角形面以形成棱柱。这些结构形成了笼子，笼子又连接起来形成四面体，这些四面体以菱形晶格拓扑结构组装。这种分层开放结构产生了一个巨大的晶胞，具有超过 800 个节点和连接器，包含直径为 5 和 6 nm 的内腔。科学，这个问题 p。624 极低密度、分级的金属有机骨架由氧配位的铀阳离子锚定。从简单的积木自下而上构建高度复杂的结构仍然是化学中最困难的挑战之一。我们报告了一种结构复杂的介孔铀基金属有机框架 (MOF)，由简单的起始成分制成。该结构包含 10 个铀节点和 7 个三羧酸盐配体（在晶体学上均不等价），从而形成一个 173.3 埃的立方晶胞，其中包含 816 个铀节点和 816 个有机连接体——迄今为止发现的任何非生物材料的最大晶胞。立方八面体组织成五边形和六边形棱柱二级结构，然后形成具有前所未有的复杂性的四面体和菱形四元拓扑。