Li Jia-Bin, Zheng Han-Wen, Wu Min, Liang Qiong-Fang, Yang Dong-Dong, Zheng Xiang-Jun, Tan Hong-Wei
Beijing Key Laboratory of Energy Conversion and Storage Materials, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China.
Inorg Chem. 2021 Dec 6;60(23):17677-17686. doi: 10.1021/acs.inorgchem.1c02286. Epub 2021 Nov 16.
A triphenylamine (TPA)-based 2-quinazoline Zn(II) complex () exhibiting dual fluorescence and phosphorescence emission in the solid state was designed and prepared. It possesses mechanochromic luminescence and thermochromic luminescence properties. In the solid state, the white afterglow luminescence could be observed at 77 K (CIE: 0.27, 0.33) while cyan luminescence could be observed at 297 K. After thermolysis at 300 °C, could be transformed into Schiff base complex with white fluorescence in the powder state (CIE: 0.32, 0.38), in methanol (CIE: 0.32, 0.39), and in dimethylformamide (CIE: 0.26, 0.32) at room temperature. This arises from dual emission of normal* emission and tautomeric* emission induced by excited-state intramolecular proton transfer (ESIPT) from the benzimidazole NH group to the Schiff base N atom. could also be transformed into its isomeric form, , through photochemical ring-opening reaction upon irradiation under 365 nm in the solution, exhibiting high-contrast photochromic luminescence. Interestingly, could further be transformed into its zwitterionic isomer after continuous irradiation. The same ring-opening reaction could also take place for the orgainc compound via heating or 365 nm irradiation. The ring-opening reaction mechanism and ESIPT emission were interpreted via theoretical calculation.
设计并制备了一种基于三苯胺（TPA）的2-喹唑啉锌（II）配合物（），该配合物在固态下呈现双荧光和磷光发射。它具有机械变色发光和热变色发光特性。在固态下，在77 K时可观察到白色余辉发光（CIE：0.27，0.33），而在297 K时可观察到青色发光。在300℃热解后，可转化为席夫碱配合物，在室温下在粉末状态（CIE：0.32，0.38）、甲醇（CIE：0.32，0.39）和二甲基甲酰胺（CIE：0.26，0.32）中具有白色荧光。这源于由激发态分子内质子转移（ESIPT）从苯并咪唑NH基团到席夫碱N原子诱导的正常发射和互变异构发射的双发射。还可通过在365 nm光照下在溶液中的光化学开环反应转化为其异构体形式，表现出高对比度的光致变色发光。有趣的是，连续照射后可进一步转化为其两性离子异构体。有机化合物也可通过加热或365 nm照射发生相同的开环反应。通过理论计算解释了开环反应机理和ESIPT发射。
