Laboratory of Organic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zurich, HCI, Vladimir-Prelog-Weg 3, 8093, Zurich, Switzerland.
Institute of Physical Chemistry and Chemical Physics, Slovak University of Technology, Radlinského 9, 81237, Bratislava, Slovakia.
Chemistry. 2020 Sep 4;26(50):11451-11461. doi: 10.1002/chem.202001788. Epub 2020 Aug 11.
Resorcin[4]arene cavitands, equipped with diverse quinone (Q) and [Ru(bpy) dppz] (bpy=2,2'-bipyridine, dppz=dipyrido[3,2-a:2',3'-c]phenazine) photosensitizing walls in different configurations, were synthesized. Upon visible-light irradiation at 420 nm, electron transfer from the [Ru(bpy) dppz] to the Q generates the semiquinone (SQ) radical anion, triggering a large conformational switching from a flat kite to a vase with a cavity for the encapsulation of small guests, such as cyclohexane and heteroalicyclic derivatives, in CD CN. Depending on the molecular design, the SQ radical anion can live for several minutes (≈10 min) and the vase can be generated in a secondary process without need for addition of a sacrificial electron donor to accumulate the SQ state. Switching can also be triggered by other stimuli, such as changes in solvent, host-guest complexation, and chemical and electrochemical processes. This comprehensive investigation benefits the development of stimuli-responsive nanodevices, such as light-activated molecular grippers.
合成了一系列带有不同醌（Q）和[Ru(bpy) dppz]（bpy=2,2'-联吡啶，dppz=二吡啶并[3,2-a:2',3'-c]吩嗪）光敏化壁的间苯二酚空腔主体。在 420nm 的可见光照射下，[Ru(bpy) dppz]向 Q 的电子转移产生半醌（SQ）自由基阴离子，引发从平面风筝到带有空腔的花瓶的大构象转变，可用于包封环己烷和杂环衍生物等小分子客体在 CD CN 中。根据分子设计，SQ 自由基阴离子可以存活几分钟（≈10 分钟），并且花瓶可以在没有添加牺牲电子供体以积累 SQ 态的情况下通过次级过程产生。通过其他刺激，如溶剂变化、主客体络合以及化学和电化学过程，也可以触发开关。这项全面的研究有助于开发对刺激有响应的纳米器件，例如光激活分子夹。
