Guan Jianping, Tu Qin, Chen Long, Yuan Mao-Sen, Wang Jinyi
College of Chemistry & Pharmacy, Northwest A&F University, Yangling, Shaanxi 712100, PR China.
College of Chemistry & Pharmacy, Northwest A&F University, Yangling, Shaanxi 712100, PR China; State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2019 Sep 5;220:117114. doi: 10.1016/j.saa.2019.05.019. Epub 2019 May 11.
Herein, we designed and synthesized a luminophor, Rh-F, which is an intergrant of rhodol and 2-hydroxy benzothiazole by introducing a benzothiazole unit onto the ortho-position of the phenolic hydroxy of rhodol. Rh-F exhibited excellent fluorescence properties such as a large Stokes shift (>180 nm) and the synergistic effect of aggregation-induced emission (AIE) and an excited state intramolecular proton transfer (ESIPT) feature. The AIE/ESIPT mechanism was thoroughly explored using X-ray single-crystal structures and photophysical determinations. Furthermore, Rh-F showed a sensitive fluorescence response to Fe with low detection limits of 115.2 nM and high selectivity. Studies of its sensing mechanism indicated that the Fe-induced blue-green fluorescence-quenched at 525 nm originates from an irreversible Fe chelate with the oxygen atom of the hydroxyl group and the N atom of the benzothiazole moiety. This blocked the ESIPT process of Rh-F which resulted in the quenching of the fluorescence sensor for Rh-F.
在此，我们设计并合成了一种发光体Rh-F，它是通过将苯并噻唑单元引入到若丹明酚羟基的邻位而得到的若丹明与2-羟基苯并噻唑的整合体。Rh-F表现出优异的荧光特性，如大斯托克斯位移（>180 nm）以及聚集诱导发光（AIE）和激发态分子内质子转移（ESIPT）特征的协同效应。利用X射线单晶结构和光物理测定对AIE/ESIPT机制进行了深入研究。此外，Rh-F对Fe表现出灵敏的荧光响应，检测限低至115.2 nM且选择性高。其传感机制研究表明，Fe诱导的在525 nm处蓝绿色荧光猝灭源于Fe与羟基的氧原子和苯并噻唑部分的N原子形成不可逆螯合物。这阻断了Rh-F的ESIPT过程，导致Rh-F荧光传感器的荧光猝灭。
