Photoreversible Switching of the Lower Critical Solution Temperature in a Photoresponsive Host-Guest System of Pillar[6]arene with Triethylene Oxide Substituents and an Azobenzene Derivative
Photoreversible Switching of the Lower Critical Solution Temperature in a Photoresponsive Host-Guest System of Pillar[6]arene with Triethylene Oxide Substituents and an Azobenzene Derivative
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DOI：
10.1021/ja3091033
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发表时间：
2012-12-12
影响因子：
15
通讯作者：
Yamagishi, Tada-aki
中科院分区：
文献类型：
--
作者：
Ogoshi, Tomoki;Kida, Kanako;Yamagishi, Tada-aki
合成了一种新的具有三氧化二乙烯基的水溶性热响应柱[6]芳烃。柱状[6]芳烃在水溶液中表现出较低的临界溶解温度行为。它的浊点是基于光响应的主客系统进行光可逆切换的。偶氮苯客体的转化与柱[6]芳烃形成稳定的1:1配合物。络合增加了浑浊点。紫外光照射导致偶氮苯客体的构象发生变化，由反式变为顺式，由于顺式与柱状[6]芳烃腔的尺寸不匹配而发生脱线。这种去线程化降低了混浊点。光响应的主客体系统是可逆的，浊点可以通过紫外或可见光的交替照射来切换。我们展示了光响应可逆透明到浑浊和浑浊到清澈的转变，该解决方案基于使用光敏主-客体系统的浑浊点可逆切换。
A new water-soluble thermoresponsive pillar[6]arene with triethylene oxide groups was synthesized. The pillar[6]arene showed lower critical solution temperature behavior in aqueous solution. Its clouding point was photoreversibly switched based on a photoresponsive host-guest system. The trans form of an azobenzene guest formed a stable 1:1 complex with the pillar[6]arene. Complexation increased the clouding point. Irradiation with UV light induced a conformation change for the azobenzene guest from the trans to cis form, and dethreading occurred because of a size mismatch between the cis form and the pillar[6]arene cavity. This dethreading decreased the clouding point. The photoresponsive host-guest system was reversible, and the clouding point could be switched by alternating irradiation with UV or visible light. We demonstrated photoresponsive reversible clear-to-turbid and turbid-to-clear transitions for the solution based on the reversible switching of the clouding point using the photosensitive host-guest system.