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, 1H NMR, and 13C 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−, H2PO4−, H2AsO4−, 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 H2PO4− and H2AsO4− 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.

A Novel Thiophene-Based Fluorescent Chemosensor for the Detection of Zn2+ and CN−: Imaging Applications in Live Cells and Zebrafish

“…In particular, cyanide has been extensively used in numerous territories like synthetic fiber, gold mining, resin industries, and metallurgy [15][16][17][18]. Thus, the voluminous usage of cyanide is ineludible, and numerous industries yield about 140 k tons/year of cyanide [19][20][21]. However, cyanide acts as a strong poison.…”

Selective colorimetric molecular probe for cyanide ion detection in aqueous solution

“…The sensing mechanism is based on either hydrogen bonding or chemodosimetry. For the hydrogen bonding mechanism a number of receptor moieties were investigated such as phenol [16], urea, thiourea [17], amides [5], Schiff bases [4,[18][19][20], squarylium ions [21] and many more are continuously developing [22].…”