Zirconium-based porous coordination cages have been widely studied and have shown to be potentially useful for many applications as a result of their tunability and stability, likely as a result of their status as a molecular equivalent to the small 8 Å tetrahedral pores of UiO-66 (Zr6(μ3-O)4(μ2-OH)4(C8O4H4)6). Functional groups attached to these molecular materials endows them with a range of tunable properties. While so-called multivariate MOFs, structures containing multiple types of functional groups on different bridging ligands within a structure are common, incorporating multiple functional moieties in permanently microporous molecular materials has proved challenging. By applying a mixed-ligand, or heteroleptic, synthesis strategy to cage formation, we have designed a straight-forward, one-pot synthesis of 10 Å zirconium-based molecular cages in a basket-shaped, or Zr12L6, geometry containing 3:3 ratios of combinations of two types of functional moieties from 11 different ligand options. Additionally, using more sterically hindered ligands, such as 5-benzyloxybenzene dicarboxylate, we show that ligand geometry governs the resulting cage geometry. This method allows for multiple functional groups to be incorporated in molecular cages and the ratio of moieties incorporated can be easily controlled. With this strategy in hand, we show that ligands for which zirconium cage syntheses have been elusive, such as 2,5-dihydroxybenzene dicarboxylate, have now been successfully incorporated into porous structures.

中文翻译：

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异质锆基多孔配位笼的可调谐合成


锆基多孔配位笼已被广泛研究，并因其可调性和稳定性而被证明可能适用于许多应用，这可能是由于它们作为分子等效于 UiO-66 （Zr6（μ3-O）4（μ2-OH）4（C8O4H4）6） 的 8 Å 四面体小孔。附着在这些分子材料上的官能团赋予了它们一系列可调特性。虽然所谓的多变量 MOFs，即在一个结构内的不同桥接配体上包含多种类型官能团的结构很常见，但在永久微孔分子材料中加入多个官能团已被证明是具有挑战性的。通过将混合配体或异源合成策略应用于笼形成，我们设计了一种直接的一锅法合成 10 Å 锆基分子笼，采用篮状或 Zr12L6 几何形状，包含 3：3 比例的来自 11 种不同配体选项的两种功能部分的组合。此外，使用空间受阻更多的配体，例如 5-苄氧基苯二羧酸盐，我们表明配体几何形状控制着所得的笼几何形状。该方法允许在分子笼中掺入多个官能团，并且可以轻松控制掺入部分的比例。有了这种策略，我们表明锆笼合成难以捉摸的配体，例如 2,5-二羟基苯二羧酸盐，现在已经成功地掺入多孔结构中。