Substituted 2-aminobenzothiazoles salicylidenes synthesis and characterization as cyanide sensors in aqueous medium

Abstract

(E)-2-((benzo[d]thiazol-2-ylimino)methyl)-4-nitrophenol 1 and (E)-2-(((6-methoxybenzo[d]thiazol-2-yl)imino)methyl)-4-nitrophenol 2 were synthesized efficiently under microwave conditions. The structures were confirmed using IR,1 H NMR, and13 C NMR. UV-vis. Fluorescence investigations demonstrated that 1 and 2 are sensitive and selective sensors for detection of cyanide over all other anions SCN?, AcO?, N3 ?, H2 PO4 ?, H2 AsO4 ?, F?, Cl?, Br?, and I? in aqueous media. Cyanide induces colorimetric change from pale yellow to dark yellow and from transparent to pale yellow for 1 and 2, respectively. It enhances the absorption at wavelengths 385 nm and 425 nm of 1 and 385 nm and 435 nm of 2. Acidic anions H2 PO4 ? and H2 AsO4 ? displayed significant interference with the interaction of cyanide and sensors 1 and 2. Sensor 1 has lower detection limit (LDL) 1 ? 10?6 M, while 2 has LDL 1.35 ? 10?6 M. ? 2018 by the authors. Licensee MDPI, Basel, Switzerland.