Design and synthesis of a novel chemosensor for simultaneous detection of CN−, HCO3− and AcO− anions and Fe2+ cation in an organic-aqueous environment: An experimental and Density Functional Theory studies

• Published in: Journal of molecular structure Vol. 1243; p. 130708
• Main Authors: Kamali, Shirin, Orojloo, Masoumeh, Amani, Saeid
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 05.11.2021
• Subjects: Azo–azomethine chemosensor; Computational study; Naked-eye detection; Azo–azomethine chemosensor; Computational study; Naked-eye detection
• ISSN: 0022-2860; 1872-8014
• DOI: 10.1016/j.molstruc.2021.130708

•A novel Schiff base ligand, namely 2-((E)-(2-(1H-indol-3-yl)ethylimino)methyl)-4-((E)-(2-nitrophenyl)diazenyl)phenol (L) was synthesized.•The receptor (L) (5 × 10−5 M) in DMF solution exhibited very good sensing behavior towards CNˉ, HCO3−, AcO− and Fe2+ ions.•The stabilization energy of the optimized complexes was more negative than the energy of free receptor (L) proving the greater stability of the formed complexes.•The reversibility of the synthesized receptor (L) was successfully approved.•The receptor (L) can be candidate as an operational colorimetric chemosensor with low-cost detection, high selectivity and nice reversibility in DMF solutions. A new azo–azomethine chemosensor, 2-((E)-(2-(1H-indol-3-yl)ethylimino)methyl)-4-((E)-(2-nitrophenyl)diazenyl)phenol, L, was synthesized and characterized by Infrared spectroscopy (IR), Ultraviolet–visible spectroscopy (UV-Visible) and Nuclear magnetic resonance spectroscopy (NMR) methods. The sensory properties of this Schiff base compound (L) were investigated in Dimethyl sulfoxide (DMSO)/H2O (9.5:0.5 v/v) solution. It was selectively sensitive to CNˉ and HCO3ˉ and AcOˉ anions, and in the presence of them, the color of solution L through deprotonating mechanism changed from yellow to orange. This chemosensor also sensitive to Fe2+. Then, by using Job's method and Benesi–Hildebrand equation, the binding stoichiometry of L with anions and binding constant (ka) were determined (CN−: 1:1, 3.47×10+5; HCO3−: 1:1, 2.44×10+5; AcO−: 1:1, 1.76×10+5), respectively. Also, the Limit of Detection (LOD) was calculated. Finally, the observed experimental results were confirmed by Density Functional Theory (DFT) calculations. A new Schiff base chemosensor, 2-((E)-(2-(1H-indol-3-yl)ethylimino)methyl)-4-((E)-(2-nitrophenyl)diazenyl)phenol, L, was synthesized. The L sensor successfully detected both cations (Fe2+) and anions (AcOˉ, CNˉ, HCO3ˉ) by the naked-eye and UV–Vis spectroscopy in an organic-aqueous environment. Through DFT calculations, the experimental results were confirmed. So, we believe that L can be an efficient sensor for detecting said ions in aqueous media. [Display omitted]