Asian Journal of Chemistry | 2021
Fluorescence Recognition of Al(III) Ions by a New Chemosensor Based\nE-4-((1-(10H-Phenothiazin-2-yl)ethylidene)amino)-N-(pyrimindin-2-yl)benzenesulfonamide
Abstract
A novel Schiff base derivative E-4-((1-(10H-phenothiazin-2-yl) ethylidene)amino)-N-(pyrimindin-2-\nyl)benzenesulfonamide (BT) was synthesized and characterized by 1H & 13C NMR, FT-IR and mass\nspectrometry. Compound BT acts as a detector for Al3+ in ethanol/water HEPES buffer solution (5\nmM, pH 7.4, v/v 1:4) at room temperature. The fluorescence intensity observed at 516 nm was increased\ndue to Al3+ ion present with a fluorescence response “turn-on” process, when excited at 290 nm. This\nshows compound BT is coordinated to Al3+ ion through the NH group and C=NH of the Schiff base\nblocking the photoinduced transfer (PET) and chelation induced enhanced fluorescence (CHEF) process,\nto increase the fluorescence intensity of BT. The detection limit of BT was in a micro-molar range for\nAl3+ ion, confirming high selectivity and sensitivity of BT. The BT-Al3+ ion binding mode and the\nrecognition mechanism of chemosensor were explored by EDTA titration, Job’s plot, Mass and FT-IR\nanalysis. The theoretical support was established by DFT calculations.