Ogoshi Tomoki, Akutsu Tomohiro, Yamagishi Tada-Aki
Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan.
WPI Nano Life Science Institute, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan.
Beilstein J Org Chem. 2018 Jul 26;14:1937-1943. doi: 10.3762/bjoc.14.167. eCollection 2018.
The hydrophobic/hydrophilic ratio in a molecule largely affects its assembled properties in aqueous media. In this study, we synthesized a new bicyclic compound which could dynamically change its hydrophobic/hydrophilic ratio by chemical stimulus. The bicyclic compound consisted of amphiphilic pillar[5]arene and hydrophobic alkyl chain rings, and formed a self-inclusion structure in aqueous media, which was assigned as a [1]catenane structure. The hydrophobic chain ring was hidden inside the pillar[5]arene cavity in the [1]catenane structure, thus the bicyclic compound was soluble in water at 20 °C with a clouding point at 24 °C. The [1]catenane was converted to the de-threaded structure upon addition of the neutral guest 1,4-dicyanobutane, which displaced the alkyl chain ring from the inside to the outside of the cavity. The hydrophobic alkyl chain ring was now exposed to the aqueous media, causing aggregation of the hydrophobic alkyl chain rings, which induced insolubilization of the bicyclic compound in aqueous media at 20 °C and a decrease in its clouding point.
分子中的疏水/亲水比例在很大程度上影响其在水性介质中的聚集性质。在本研究中，我们合成了一种新型双环化合物，其可通过化学刺激动态改变疏水/亲水比例。该双环化合物由两亲性柱[5]芳烃和疏水烷基链环组成，并在水性介质中形成自包结结构，被指定为[1]索烃结构。在[1]索烃结构中，疏水链环隐藏在柱[5]芳烃腔内，因此该双环化合物在20℃时可溶于水，浊点为24℃。加入中性客体1,4 - 二氰基丁烷后，[1]索烃转变为解索结构，烷基链环从腔内被置换到腔外。此时疏水烷基链环暴露于水性介质中，导致疏水烷基链环聚集，从而使双环化合物在20℃的水性介质中不溶，并使其浊点降低。
