Design of a near-infrared fluorescent sensor for detecting fluoride anion based on 10-hydroxybenzo[h]quinoline: a theoretical study

The design of near-IR fluorescence sensors is of significant importance for various in vivo applications. In this context, a convenient platform is provided by 10-hydroxybenzo-[h]quinoline (HBQ), in which intramolecular excited-state proton transfer occurs. In this work, a systematic theoretical study was conducted of five HBQ derivatives, involving an analysis of the molecular geometry during proton transfer in both the ground (S0) and excited (S1) states. The potential of the HBQ derivatives for detecting F−, Cl−, and Br− anions was assessed based on the results of comprehensive analysis of their calculated photophysical characteristics. It was demonstrated that the strategy involving simultaneous addition of electron-withdrawing and electron-donating groups to carbon atoms of the HBQ proton donor ring and proton acceptor ring, respectively, makes it possible to obtain high-performance near-IR fluorescent sensors. © 2025 Elsevier B.V., All rights reserved.