Institute of Molecular Plus (IMP), Tianjin University, Tianjin 300072, P. R. China.
Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing 100048, P. R. China.
J Am Chem Soc. 2022 Jul 20;144(28):12652-12660. doi: 10.1021/jacs.2c01248. Epub 2022 Jun 28.
Stimuli-responsive functional luminescent materials with tunable color and long-persistent emission have emerged as a powerful tool in information encryption, anticounterfeiting, and bioelectronics. Herein, we prove a novel strategy for manipulating the proton transfer pathways in the salicylaldehyde derivative EQCN solutions/powder to produce excitation wavelength-dependent (Ex-De) performances with switchable emissions (blue-sky, green, and orange). The experiments and theoretical results demonstrated that the different luminous colors are originated from enol (E) form (blue-sky), Keto-1 (K1) form (orange) through the excited-state intramolecular proton transfer (ESIPT) process, and Keto-2 (K2) form (green) through the excited-state long-range proton transfer (ESLRPT) process. We leverage synergistic effects between the dopant and matrix (dimethyl terephthalate, DTT) to manipulate the excited-state proton transfer pathway in EQCN@DTT mixture powders to generate Ex-De long-persistent luminescence (Ex-De-LPL), which can be well applied in multilevel information encryption. This strategy not only paves an intriguing way for the construction and preparation of pure organic Ex-De materials but also offers a guideline for developing LPL materials based on ESLRPT processes.
具有可调颜色和长余辉发射的刺激响应功能发光材料已成为信息加密、防伪和生物电子学的有力工具。在此，我们证明了一种新的策略，可以操纵水杨醛衍生物 EQCN 溶液/粉末中的质子转移途径，以产生具有可切换发射（天蓝色、绿色和橙色）的激发波长依赖性（Ex-De）性能。实验和理论结果表明，不同的发光颜色源自烯醇（E）形式（天蓝色）、酮-1（K1）形式（橙色）通过激发态分子内质子转移（ESIPT）过程，以及酮-2（K2）形式（绿色）通过激发态远程质子转移（ESLRPT）过程。我们利用掺杂剂和基质（对苯二甲酸二甲酯，DTT）之间的协同效应，操纵 EQCN@DTT 混合物粉末中的激发态质子转移途径，以产生 Ex-De 长余辉发光（Ex-De-LPL），可广泛应用于多级信息加密。该策略不仅为构建和制备纯有机 Ex-De 材料开辟了一条有趣的途径，而且为基于 ESLRPT 过程的长余辉材料的发展提供了指导。
