EaStCHEM School of Chemistry, University of St Andrews, Purdie Building, St Andrews, UK.
Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
Nat Chem. 2018 Nov;10(11):1096-1102. doi: 10.1038/s41557-018-0104-x. Epub 2018 Aug 13.
Highly porous metal-organic frameworks (MOFs), which have undergone exciting developments over the past few decades, show promise for a wide range of applications. However, many studies indicate that they suffer from significant stability issues, especially with respect to their interactions with water, which severely limits their practical potential. Here we demonstrate how the presence of 'sacrificial' bonds in the coordination environment of its metal centres (referred to as hemilability) endows a dehydrated copper-based MOF with good hydrolytic stability. On exposure to water, in contrast to the indiscriminate breaking of coordination bonds that typically results in structure degradation, it is non-structural weak interactions between the MOF's copper paddlewheel clusters that are broken and the framework recovers its as-synthesized, hydrated structure. This MOF retained its structural integrity even after contact with water for one year, whereas HKUST-1, a compositionally similar material that lacks these sacrificial bonds, loses its crystallinity in less than a day under the same conditions.
高度多孔的金属-有机骨架（MOFs）在过去几十年中经历了令人兴奋的发展，它们在广泛的应用中具有很大的潜力。然而，许多研究表明它们存在严重的稳定性问题，特别是在与水的相互作用方面，这严重限制了它们的实际应用潜力。在这里，我们展示了在其金属中心的配位环境中存在“牺牲”键（称为半配位）如何赋予脱水的铜基 MOF 良好的水解稳定性。与通常导致结构降解的配位键无差别断裂相反，在暴露于水时，MOF 的铜桨轮簇之间的非结构弱相互作用被打破，而框架恢复其合成的、水合的结构。这种 MOF 即使在与水接触一年后也保持其结构完整性，而 HKUST-1 是一种组成相似但缺乏这些牺牲键的材料，在相同条件下不到一天就失去了结晶度。
