Onishi Katsuto, Ohtani Shunsuke, Kato Kenichi, Fa Shixin, Sakata Yoko, Akine Shigehisa, Ogasawara Moe, Asakawa Hitoshi, Nagano Shusaku, Takashima Yoshinori, Mizuno Motohiro, Ogoshi Tomoki
Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University Katsura, Nishikyo-ku Kyoto 615-8510 Japan
WPI Nano Life Science Institute (WPI-NanoLSI), Kanazawa University Kakuma-machi Kanazawa Ishikawa 920-1192 Japan.
Chem Sci. 2022 Mar 16;13(14):4082-4087. doi: 10.1039/d2sc00828a. eCollection 2022 Apr 6.
Molecular glasses are low-molecular-weight organic compounds that are stable in the amorphous state at room temperature. Herein, we report a state- and water repellency-controllable molecular glass by -alkane guest vapors. We observed that a macrocyclic host compound pillar[5]arene with the CF fluoroalkyl groups changes from the crystalline to the amorphous state (molecular glass) by heating above its melting point and then cooling to room temperature. The pillar[5]arene molecular glass shows reversible transitions between amorphous and crystalline states by uptake and release of the -alkane guest vapors, respectively. Furthermore, the -alkane guest vapor-induced reversible changes in the water contact angle were also observed: water contact angles increased and then reverted back to the original state by the uptake and release of the -alkane guest vapors, respectively, along with the changes in the chemical structure and roughness on the surface of the molecular glass. The water repellency of the molecular glass could be controlled by tuning the uptake ratio of the -alkane guest vapor.
分子玻璃是在室温下处于非晶态时稳定的低分子量有机化合物。在此，我们报道了一种通过正构烷烃客体蒸汽实现状态和拒水性可控的分子玻璃。我们观察到，带有CF氟烷基的大环主体化合物柱[5]芳烃在加热至熔点以上然后冷却至室温时，会从晶态转变为非晶态（分子玻璃）。柱[5]芳烃分子玻璃分别通过吸收和释放正构烷烃客体蒸汽，在非晶态和晶态之间呈现可逆转变。此外，还观察到正构烷烃客体蒸汽诱导的水接触角可逆变化：随着分子玻璃表面化学结构和粗糙度的变化，水接触角分别通过吸收和释放正构烷烃客体蒸汽而增大，然后恢复到原始状态。分子玻璃的拒水性可以通过调节正构烷烃客体蒸汽的吸收比例来控制。
