Opening the Gate: Framework Flexibility in ZIF-8 Explored by Experiments and Simulations
Opening the Gate: Framework Flexibility in ZIF-8 Explored by Experiments and Simulations
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DOI：
10.1021/ja202154j
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发表时间：
2011-06-15
影响因子：
15
通讯作者：
Dueren, T.
中科院分区：
文献类型：
--
作者：
Fairen-Jimenez, D.;Moggach, S. A.;Dueren, T.
ZIF-8是一种具有由窄窗口互连的大空腔的沸石咪唑基金属有机框架。由于窗口尺寸小，原则上允许气体如H-2和CH 4的分子筛。然而，大分子在ZIF-8上的意外吸附表明存在结构灵活性。ZIF-8的灵活性在这项工作中探索结合不同的实验技术与分子模拟。我们表明，ZIF-8结构通过气体吸附吸收以与在非常高的压力下相同的方式进行改性（即，14 700巴），这是由于咪唑酯连接体中的摆动效应，从而获得孔隙率。调整柔性以及小窗口的打开对用于气体分离的先进分子筛膜材料的设计具有进一步的影响，从而调整流体进入多孔网络。
ZIF-8 is a zeolitic imidazole-based metal-organic framework with large cavities interconnected by narrow windows. Because the small size of the windows, it allows in principle for molecular sieving of gases such as H-2 and CH4. However, the unexpected adsorption of large molecules on ZIF-8 suggests the existence of structural flexibility. ZIF-8 flexibility is explored in this work combining different experimental techniques with molecular simulation. We show that the ZIF-8 structure is modified by gas adsorption uptake in the same way as it is at a very high pressure (i.e., 14 700 bar) due to a swing effect in the imidazolate linkers, giving access to the porosity. Tuning the flexibility, and so the opening of the small windows, has a further impact on the design of advanced molecular sieving membrane materials for gas separation, adjusting the access of fluids to the porous network.