Kang Taewon, Kim Hongsik, Jeoung Sungeun, Moon Dohyun, Moon Hoi Ri, Lee Dongwhan
Department of Chemistry, Seoul National University 1 Gwanak-ro, Gwanak-gu Seoul 08826 Korea
Ulsan National Institute of Science and Technology (UNIST) 50 UNIST-gil, Eonyang-eup, Ulji-gun Ulsan 44919 Korea.
Chem Sci. 2021 Apr 1;12(18):6378-6384. doi: 10.1039/d1sc01163d.
With small molecules, it is not easy to create large void spaces. Flat aromatics stack tightly, while flexible chains fold to fill the cavities. As an intuitive design to make open channels inside molecularly constructed solids, we employed propeller-shaped bicyclic triazoles to prepare a series of aromatic-rich three-dimensional (3D) building blocks. This modular approach has no previous example, but is readily applicable to build linear, bent, and branched arrays of non-stackable architectural motifs from existing flat aromatics by single-pot reactions. A letter H-shaped molecule thus prepared self-assembles into porous crystals, the highly unusual stepwise gas sorption behaviour of which prompted in-depth studies. A combination of single-crystal and powder X-ray diffraction analysis revealed multiple polymorphs, and sterically allowed pathways for their reversible interconversions that open and close the pores in response to external stimuli.
对于小分子而言，创造大的空隙空间并非易事。扁平芳烃紧密堆积，而柔性链则折叠以填充空隙。作为在分子构建的固体内部制造开放通道的直观设计，我们采用螺旋桨状双环三唑来制备一系列富含芳烃的三维（3D）结构单元。这种模块化方法此前并无先例，但通过单锅反应，很容易应用于从现有的扁平芳烃构建不可堆叠建筑基序的线性、弯曲和分支阵列。如此制备的一个字母H形分子自组装成多孔晶体，其高度不寻常的逐步气体吸附行为促使进行深入研究。单晶和粉末X射线衍射分析相结合揭示了多种多晶型物，以及它们可逆相互转化的空间允许途径，这些途径可响应外部刺激打开和关闭孔隙。
