Inspired by natural systems, metal-organic cages with well-defined shapes and cavities can be tuned for different guest-binding functions. Here, we report the construction of two types of cage frameworks: an MII12L8 (M = ZnII and CoII) pseudo-cuboctahedral architecture 1 and a rarer MII9L8 (M = ZnII and CoII) pseudo-Johnson-solid-type (J51) framework 2. Both structures form from the same boron-containing triamine subcomponent, and each one incorporates hexacoordinate metal vertices chelated by only two bidentate pyridyl(imine) arms. Such vertices provide the cages with the flexibility required to form lower-symmetry architectures, and they also facilitate reversible disassembly in response to fluoride. These cages were also shown to respond to other chemical stimuli enabling transformation between cage structures. Cage 1 bound different guest molecules, including the anticancer drug paclitaxel, C-methylcalix[4]resorcinarene, and tetraphenylborates. The release of paclitaxel by 1 was stimulated by fluoride or chloride, highlighting the potential for applications in natural product separation and drug delivery.

中文翻译：

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客体结合由包含双吡啶基（亚胺）顶点的低对称金属有机笼中的多个刺激控制


受自然系统的启发，具有明确形状和空腔的金属有机笼子可以针对不同的客体绑定功能进行调整。在这里，我们报告了两种类型的笼框架的构建：一种MII12L8 （M = ZnII 和 CoII） 伪立方八面体结构 1 和更罕见的 MII9L8 （M = ZnII 和 CoII） 伪约翰逊固体型 （J51） 框架 2。两种结构由相同的含硼三胺亚组分形成，并且每个结构都包含仅由两个双齿吡啶（亚胺）臂螯合的六坐标金属顶点。这些顶点为笼子提供了形成低对称性结构所需的灵活性，并且它们还有助于响应氟化物的可逆分解。这些笼子还被证明对其他化学刺激做出反应，从而能够在笼子结构之间发生转变。Cage 1 结合不同的客体分子，包括抗癌药物紫杉醇、C-甲基钙[4]间苯二烯和四苯硼酸盐。氟化物或氯化物刺激 1 释放紫杉醇，突出了在天然产物分离和药物递送中的应用潜力。