Department of Chemistry & IRIS Adlershof, Humboldt-Universität zu Berlin, Brook-Taylor-Strasse 2, Berlin 12489, Germany.
DWI-Leibniz Institute for Interactive Materials & Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, Forckenbeckstrasse 50, Aachen 52074, Germany.
J Am Chem Soc. 2021 Jun 23;143(24):9162-9168. doi: 10.1021/jacs.1c03631. Epub 2021 Jun 11.
Cyanodiarylethene chromophores are able to undergo constitutional exchange via dynamic covalent chemistry (DCC). During this process, the central ethylene bridge of the molecular scaffold can be broken and thereby enables the assembly of a new combination of aryl moieties around the reformed ethylene bridge. The reversible C═C double bond exchange has exemplarily been investigated using α-cyanostilbenes. Establishing a dynamic equilibrium reaction from α-cyanodiarylethene with arylacetonitriles under mild conditions has been the basis to access constitutional libraries of new photoswitches with potentially improved properties. When subject to irradiation with light of adequate wavelength, α-cyanodiarylethenes undergo / isomerization followed by ring-closure. By screening the thus accessible dynamic chromophore libraries using a desired detection wavelength, we could identify specific dithienyl analogues that exhibit three-state photochromism. The combination of dynamic constitutional libraries of functional chromophores in combination with the light-guided screening and selection should lead to more rapid exploration of structural diversity dye chemistry.
二芳基乙烯发色团能够通过动态共价化学（DCC）进行构象交换。在此过程中，分子支架的中心乙烯桥可以被打断，从而使围绕新形成的乙烯桥的芳基部分组合方式发生改变。使用α-氰基苯乙烯对可逆的 C═C 双键交换进行了示例研究。在温和条件下，α-氰基二芳基乙烯与芳基乙腈之间建立动态平衡反应，是获得具有潜在改进性能的新型光开关的构象库的基础。当用适当波长的光照射时，α-氰基二芳基乙烯会发生异构化，随后环化。通过使用所需的检测波长筛选由此可得的动态发色团库，我们可以鉴定出表现出三态光致变色的特定二噻吩类似物。功能发色团的动态构象库的组合与光引导的筛选和选择相结合，应该会加速对结构多样性染料化学的探索。
