School of Chemical Engineering and Technology, Hebei University of Technology, GuangRong Dao 8, Hongqiao District, Tianjin, 300130, P. R. China.
Angew Chem Int Ed Engl. 2018 Feb 19;57(8):2194-2198. doi: 10.1002/anie.201712670. Epub 2018 Jan 18.
We report herein on remote control over a reversible phase transition of robust luminescent hybrid hydrogels as enabled by the rational selection and incorporation of photoswitches. Azobenzene units functionalized with a guanidinium group were utilized as the photoswitches and incorporated through a host-guest inclusion method involving α-cyclodextrins functionalized with 2,6-pyridinedicarboxylic acid (PDA) groups. While the guanidinium functional groups bind to the negatively charged Laponite matrix surface to connect organic and inorganic components, the PDA groups enable simultaneous coordination with different lanthanide metal ions, thus rendering the hydrogel broadly luminescent. Owing to its conformation-dependent binding behavior with α-cyclodextrin, the isomerization of azobenzene induced association or dissociation of the inclusion complexes and thus lead to a reversible photocontrolled sol↔gel phase transition of the luminescent hybrid hydrogels.
我们在此报告了通过合理选择和引入光开关，实现对坚固的发光杂化水凝胶的可逆相转变的远程控制。用胍基官能化的偶氮苯单元被用作光开关，并通过涉及用 2,6-吡啶二甲酸（PDA）基团官能化的α-环糊精的主体-客体包合方法掺入。虽然胍基官能团结合到带负电荷的 Laponite 基质表面以连接有机和无机成分，但 PDA 基团能够同时与不同的镧系金属离子配位，从而使水凝胶具有广泛的发光性。由于其与α-环糊精的构象依赖性结合行为，偶氮苯的异构化诱导了包含复合物的缔合或解离，从而导致发光杂化水凝胶的可逆光控溶胶-凝胶相转变。
