Yu Xue-Fang, Xiao Bo, Cheng Jianbo, Liu Zhen-Bo, Yang Xin, Li Qingzhong
The Laboratory of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Yantai University, Yantai 264005, People's Republic of China.
ACS Omega. 2019 Jun 18;4(6):10516-10523. doi: 10.1021/acsomega.9b00693. eCollection 2019 Jun 30.
Proper design and development of near-infrared (NIR) fluorescent sensors is very important for applications in vivo. In this work, we theoretically designed a ratiometric and NIR fluorescent sensor based on the 10-hydroxybenzo[]quinoline (HBQ) backbone via systematically investigating the substituent effects of electron-donating groups (-NH, -CH, -C(CH)) and electron-withdrawing groups (-NO, -CN, -F, -Cl, -CF) at the proton donor site on the proton transfer process in HBQ in both the S and the S states. According to the calculated potential energy profiles along the proton transfer as well as the photophysical properties among all the derivatives, we successfully screened out that 7NH-HBQ is a promising fluorescent sensor exhibiting the near IR emission spectra accompanied by the large Stokes shift. The potential use of 7NH-HBQ for F detection among anions (F, Cl, and Br) was further studied, and the results showed that 7NH-HBQ is very sensitive and selective toward F based on the intermolecular hydrogen bonding interaction between F and OH bond, forming a new complex FAC . The ratiometric change in the fluorescence intensity could be induced by the H-F bond transfer from the O atom to the N atom in the S state.
近红外（NIR）荧光传感器的合理设计与开发对于体内应用非常重要。在这项工作中，我们通过系统研究给电子基团（-NH、-CH、-C(CH)）和吸电子基团（-NO、-CN、-F、-Cl、-CF）在质子供体位点对处于S0和S1态的10-羟基苯并喹啉（HBQ）骨架中质子转移过程的取代基效应，从理论上设计了一种基于HBQ骨架的比率型近红外荧光传感器。根据沿质子转移计算的势能剖面图以及所有衍生物的光物理性质，我们成功筛选出7NH-HBQ是一种有前景的荧光传感器，其呈现近红外发射光谱并伴有大斯托克斯位移。进一步研究了7NH-HBQ在阴离子（F-、Cl-和Br-）中用于F-检测的潜在用途，结果表明，基于F-与OH键之间的分子间氢键相互作用，7NH-HBQ对F-非常敏感且具有选择性，形成了一种新的配合物F-Ac。在S1态下，H-F键从O原子转移到N原子可诱导荧光强度的比率变化。
