Theoretical study of thiazole derivatives as chemosensors for fluoride anion

Abstract

The interactions between chemosensor, 2-(2′-hydroxyphenyl)-4-phenylthiazole ( 1), and different halides (F −, Cl −, and Br −) and NO 3 − anions have been theoretically investigated at the B3LYP/6-31G(d) level with the BSSE correction. It turned out that the unique selectivity of 1 for F − is ascribed to its ability of deprotonating the hydroxy group of host sensor. The intermolecular proton transfer (IPT) causes the colorimetric and fluorescent signaling of 1 for F −. The deprotonated complex 1 −·HF is formed for the deprotonation process of chemosensor. The study of substituent effects suggest that the electron-donating –CH 3 and –OCH 3 substituted derivatives are expected to be promising candidates for ratiometric fluorescent F − chemosensors as well as chromogenic chemosensors, while electron-donating –N(CH 3) 2 substituted derivative can serve as chromogenic F − chemosensors only. Furthermore, the electron-withdrawing (–NO 2 and –Br) substituted derivatives can serve as chromogenic F −/CH 3COO − chemosensors.