Synthesis, Characterization and Selective Fluorimetric Detection of Al3+ by A Schiff Base Derived From 5-Chloro-8-Hydroxyquinoline

Abstract

In this study, an aldehyde derivative compound containing 5-chloro-8-hydroxyquinoline was synthesized based on literature procedures. Subsequently, the target compound, a Schiff base derivative (HQBH), was obtained via a condensation reaction between the quinoline-based aldehyde and benzaldehydehydrazone. The chemical structure of the synthesized HQ-BH compound was confirmed using various spectroscopic techniques, including FT-IR, TOF-MS, 1H-NMR, and 13C-NMR. Next, the interactions of the HQBH compound with various metal ions (Li+, Ni2+, Co2+, Ag, Al3+, Mg2+, Mn2+, Ca2+, Ba2+, Cu2+, Hg2+, Fe2+, Rb2+,Fe3+, Cs+, Cd2+) were investigated under suitable conditions using fluorescence spectrophotometry. Initially, aselectivity study was performed. The sensor HQ-BH did not exhibit any significant fluorescence emission at 499nm upon excitation at 360 nm. However, upon the individual addition of each cation (20.0 equivalents), only Al³⁺induced a distinct emission band at 499 nm with a notable enhancement in intensity. As a result of thesemeasurements, it was concluded that the HQ-BH compound displays selective fluorimetric response exclusivelytoward Al³⁺ among all tested metal ions.