Melaugh Gavin, Giri Nicola, Davidson Christine E, James Stuart L, Del Pópolo Mario G
Atomistic Simulation Centre, School of Mathematics and Physics, Queen's University Belfast, BT7 1NN, UK.
Phys Chem Chem Phys. 2014 May 28;16(20):9422-31. doi: 10.1039/c4cp00582a.
Standard microporous materials are typically crystalline solids that exhibit a regular array of cavities of uniform size and shape. Packing and directional bonding between molecular building blocks give rise to interstitial pores that confer size and shape-specific sorption properties to the material. In the liquid state interstitial cavities are transient. However, permanent and intrinsic "pores" can potentially be built into the structure of the molecules that constitute the liquid. With the aid of computer simulations we have designed, synthesised and characterised a series of liquids composed of hollow cage-like molecules, which are functionalised with hydrocarbon chains to make them liquid at accessible temperatures. Experiments and simulations demonstrate that chain length and size of terminal chain substituents can be used to tune, within certain margins, the permanence of intramolecular cavities in such neat liquids. Simulations identify a candidate "porous liquid" in which 30% of the cages remain empty in the liquid state. Absorbed methane molecules selectively occupy these empty cavities.
标准微孔材料通常是晶体固体，具有规则排列的大小和形状均匀的孔洞。分子构建单元之间的堆积和定向键合产生了间隙孔，赋予材料尺寸和形状特异性吸附特性。在液态下，间隙空洞是短暂的。然而，永久性和固有的“孔”有可能构建在构成液体的分子结构中。借助计算机模拟，我们设计、合成并表征了一系列由空心笼状分子组成的液体，这些分子用烃链进行功能化，使其在可达到的温度下呈液态。实验和模拟表明，在一定范围内，可以利用链长和末端链取代基的大小来调节此类纯液体中分子内腔的永久性。模拟确定了一种候选“多孔液体”，其中30%的笼在液态下保持为空。吸附的甲烷分子选择性地占据这些空穴。
