Ovalle Marco, Doellerer Daniel, Feringa Ben L
Stratingh Institute for Chemistry, Center for Systems Chemistry and Zernike Institute for Advanced Materials, Faculty of Mathematics and Natural Sciences, University of Groningen, Nijenborgh 3, Groningen, 9747 AG, the Netherlands.
Angew Chem Int Ed Engl. 2025 May 26;64(22):e202501872. doi: 10.1002/anie.202501872. Epub 2025 Apr 2.
Manipulation of molecular geometry using photoresponsive units is a powerful tool in supramolecular chemistry, smart materials, and photopharmacology. Current synthetic chemistry offers many responsive molecules that perform such a task. However, the incorporation of various photoresponsive units in a single molecule to achieve several geometrical changes remains scarce, particularly when they are in close proximity. The development of such systems is limited by challenges arising from selectively addressing the photoresponsive moieties and the analysis of complex mixtures. Here, we overcome these challenges by constructing a novel hetero-photochromic azobenzene-oxindole dyad (AOD). Both chromophores can be addressed and quantified in solution by in situ NMR irradiation analysis. Additionally, this method allows us to unravel the intricate photokinetic relationships between the two chromophores, leading to the observation of an unprecedented molecular motion: an azobenzene E → Z → E isomerization at a single wavelength due to the oxindole influence. By functionalizing the azobenzene ring, we showed that the responsiveness of the system is maintained in seven distinct AODs. Overall, the photochromic dyad offers dramatic geometrical changes over its four isomers, making it a useful tool for further applications in which such behavior is desired, such as host-guest systems, responsive materials, photopharmacology, and molecular machines.
利用光响应单元操纵分子几何结构是超分子化学、智能材料和光药理学中的一种强大工具。当前的合成化学提供了许多能执行此任务的响应性分子。然而，在单个分子中引入各种光响应单元以实现多种几何变化的情况仍然很少，特别是当它们彼此靠近时。此类系统的发展受到选择性处理光响应部分以及分析复杂混合物所带来挑战的限制。在这里，我们通过构建一种新型的杂光致变色偶氮苯 - 氧化吲哚二元体系（AOD）克服了这些挑战。两种发色团都可以通过原位核磁共振照射分析在溶液中进行定位和定量。此外，这种方法使我们能够揭示两种发色团之间复杂的光动力学关系，从而观察到一种前所未有的分子运动：由于氧化吲哚的影响，偶氮苯在单一波长下发生E→Z→E异构化。通过对偶氮苯环进行功能化，我们表明该体系的响应性在七种不同的AOD中得以保持。总体而言，这种光致变色二元体系在其四种异构体上呈现出显著的几何变化，使其成为进一步应用（如主客体系统、响应材料、光药理学和分子机器等需要此类行为的应用）中的一种有用工具。
