Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa, 920-1192, Japan.
WPI Nano Life Science Institute, Kanazawa University, Kanazawa, 920-1192, Japan.
Chemistry. 2019 Feb 18;25(10):2497-2502. doi: 10.1002/chem.201805733. Epub 2019 Jan 25.
Host-guest complexation has been mainly investigated in solution, and it is unclear how guest molecules access the assembled structures of host and dynamics of guest molecules in the crystal state. In this study, we studied the uptake, release, and molecular dynamics of n-hexane vapor in the crystal state of pillar[5]arenes bearing different substituents. Pillar[5]arene bearing 10 ethyl groups yielded a crystal structure of herringbone-type 1:1 complexes with n-hexane, whereas pillar[5]arene with 10 allyl groups formed 1:1 complexes featuring a one-dimensional (1D) channel structure. For pillar[5]arene bearing 10 benzyl groups, one molecule of n-hexane was located in the cavity of pillar[5]arene, and another n-hexane molecule was located outside of the cavity between two pillar[5]arenes. The substituent-dependent differences in molecular arrangement influenced the uptake, release, and molecular dynamics of the n-hexane guest. The substituent effects were not observed in host-guest chemistry in solution, and these features are unique for the crystal state host-guest chemistry of pillar[5]arenes.
主客体络合主要在溶液中进行研究，不清楚客体分子如何进入主体的组装结构以及在晶体状态下客体分子的动力学。在这项研究中，我们研究了带有不同取代基的杯[5]芳烃晶体中 n-己烷蒸气的吸收、释放和分子动力学。带有 10 个乙基的杯[5]芳烃生成了与 n-己烷的鱼骨型 1:1 配合物的晶体结构，而带有 10 个烯丙基的杯[5]芳烃形成了具有一维（1D）通道结构的 1:1 配合物。对于带有 10 个苄基的杯[5]芳烃，一个 n-己烷分子位于杯[5]芳烃的空腔中，另一个 n-己烷分子位于两个杯[5]芳烃之间的空腔外。分子排列的取代基依赖性差异影响 n-己烷客体的吸收、释放和分子动力学。在溶液中的主客体化学中没有观察到取代基效应，这些特征是杯[5]芳烃晶体状态主客体化学所特有的。
