Electronic effect on the optical properties and sensing ability of AIEgens with ESIPT process based on salicylaldehyde azine  

作　　者：Zhiming Wang Fan Zhou Jing Wang Zujin Zhao Anjun Qin Zhenqiang Yu Ben Zhong Tang 

机构地区：[1]State Key Laboratory of Luminescent Materials and Devices, South China University of Technology，Guangzhou 510640, China [2]HKUST-Shenzhen Research Institute, Shenzhen 518057, China [3]School of Petrochemical Engineering, Shenyang University of Technology (SUT), Liaoyang 111003, China [4]College of Chemistry and Environmental, Shenzhen University, Shenzhen 518000, China [5]Department of Chemistry, The Hong Kong University of Science & Technology (HKUST), Hong Kong 999077, China

出　　处：《Science China Chemistry》2018年第1期76-87,共12页中国科学（化学英文版）

基　　金：supported by the National Natural Science Foundation of China (51673118, 51273053);the Key Project of the Ministry of Science and Technology of China (2013CB834702);the Natural Science Fund of Guangdong Province (2014A030313659,2014A030306035, 2016A030312002);the Fundamental Research Funds for the Central Universities (2015ZY013);the Innovation and Technology Commission of Hong Kong (ITC-CNERC14SC01);the Science and Technology Plan of Shenzhen (JCYJ20160428150429072);the Fundamental Research Funds for the Central Universities (2017JQ013);Guangdong Innovative Research Team Program (201101C0105067115)

摘　　要：Two novel AIE-active salicylaldehyde azine(SAA) derivatives with a typical excited-state intramolecular proton transfer(ESIPT) process are prepared by introducing electron-withdrawing and donating groups at para-position of phenolic hydroxyl group(CN-SAA and TPA-SAA). The effect of the proton activity in SAA framework on their optical behaviors is investigated spectroscopically. The results from NMR and solvation measurements show that the proton of phenolic hydroxyl group has higher activity when there are electron-withdrawing groups, and the absorption and fluorescence spectra in buffers with different pH also provide the same results. After inviting F. as a nucleophilic probe, this proton activity difference in CN-SAA and TPA-SAA becomes more obvious. The potential application of both molecules is investigated. TPA-SAA exhibits good quantitative sensing ability towards F. with a fluorescence "turn-on" mode, whereas the aggregates of TPA-SAA can selectively and sensitively detect Cu2+ in aqueous solution. From these results, a structure-property relationship is established: the occurrence of ESIPT process will become much easier when linking electron-withdrawing groups at the para-position of phenolic hydroxyl group(e.g., CN-SAA),and it is better to introduce electron-donating groups to enhance the sensing ability towards ions(e.g., TPA-SAA). This work will provide guidance for further design and preparation of AIE-active luminogens with ESIPT process for sensing applications.Two novel AIE-active salicylaldehyde azine （SAA） derivatives with a typical excited-state intramolecular proton transfer （ESIPT） process are prepared by introducing electron-withdrawing and donating groups at para-position of phenolic hydroxyl group （CN-SAA and TPA-SAA）. The effect of the proton activity in SAA framework on their optical behaviors is investigated spectroscopically. The results from NMR and solvation measurements show that the proton of phenolic hydroxyl group has higher activity when there are electron-withdrawing groups, and the absorption and fluorescence spectra in buffers with different pH also provide the same results. After inviting F- as a nucleophilic probe, this proton activity difference in CN-SAA and TPA-SAA becomes more obvious. The potential application of both molecules is investigated. TPA-SAA exhibits good quantitative sensing ability towards F with a fluorescence ＂turn-on＂ mode, whereas the aggregates of TPA-SAA can selectively and sensitively detect Cu2＋ in aqueous solution. From these results, a structure-property relationship is established： the occurrence of ESIPT process will become much easier when linking electron-withdrawing groups at the para-position of phenolic hydroxyl group （e.g., CN-SAA）, and it is better to introduce electron-donating groups to enhance the sensing ability towards ions （e.g., TPA-SAA）. This work will provide guidance for further design and preparation of AIE-active luminogens with ESIPT process for sensing applications.

关 键 词：ALE ESIPT electronic effect proton activity ion sensor 

分 类 号：N0[自然科学总论—科学技术哲学]