A porous organic cage crystal, α-CC2, shows unexpected adsorption of sulphur hexafluoride (SF₆) in its cage cavities: analysis of the static crystal structure indicates that SF₆ is occluded, as even the smallest diatomic gas, H₂, is larger than the window of the cage pore. Herein, we use in situ powder X-ray diffraction (PXRD) experiments to provide unequivocal evidence for the presence of SF₆ inside the ‘occluded’ cage voids, pointing to a mechanism of dynamic flexibility of the system. By combining PXRD results with molecular dynamics simulations, we build a molecular level picture of the cooperative porosity in α-CC2 that facilitates the passage of SF₆ into the cage voids.

中文翻译：

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利用原位衍射和分子模拟探索有机笼状晶体中的合作孔隙度

多孔有机笼状晶体α-CC2在其笼状腔中显示出六氟化硫（SF ₆）的意外吸附：对静态晶体结构的分析表明，即使最小的双原子气体H ₂都较大，SF ₆也被吸留。比笼孔的窗口大。本文中，我们使用原位粉末X射线衍射（PXRD）实验提供了明确的证据，证明了“封闭的”笼状空隙中SF ₆的存在，指出了系统动态灵活性的机制。通过将PXRD结果与分子动力学模拟相结合，我们构建了α-CC2中协同孔隙的分子水平图，这有助于SF的通过₆进入笼子空隙。