A robust, yet flexible, Al-based metal-organic framework (MOF), Al₂(OH)₂(bpydc)·0.5H₂O (1np), is synthesized via a hydrothermal strategy utilizing 2,2′-bipyridine-5,5′-dicarboxylate (bpydc^2–) as the organic ligand. The structure of 1np is built from infinite trans chains of corner-sharing AlO₄(OH)₂ octahedra interconnected by bpydc^2– ligands, forming a three-dimensional framework. 1np is robust, because of its superior thermal, hydrothermal, and chemical stability. The flexibility of 1np is reflected in the activation by the removal of unreacted H₂bpydc molecules and/or occluded solvent molecules, followed by degassing at 250 °C, leading to the large pore form (1lp) of the title compound. A reversible structural change from 1lp to 1np is achieved via the hydration in water at 200 °C. The unusual combination of rigidity and flexibility enables precise control and fixation of the swelling magnitude in this MOF material.

中文翻译：

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具有温度诱导呼吸作用的坚固的铝金属有机框架

通过使用2,2'-联吡啶-的水热策略合成了一种坚固而灵活的铝基金属有机骨架（MOF）Al ₂（OH）₂（bpydc）· 0.5H ₂ O（1 np）。 5,5'-二羧酸盐（bpydc ^2–）作为有机配体。1 np的结构由角共享的AlO ₄（OH）₂八面体的无限反式链构建，这些链通过bpydc ^2–配体互连，形成三维框架。1 np坚固，因为它具有出色的热，水热和化学稳定性。的灵活性通过除去未反应的H ₂ bpydc分子和/或封闭的溶剂分子，然后在250°C脱气，在活化中反映出1 np，从而导致标题化合物的大孔形式（1 lp）。通过在200°C的水中水合，可实现从1 lp到1 np的可逆结构变化。刚度和柔韧性的非凡组合可以精确控制和固定这种MOF材料中的膨胀量。