Abstract:

A colorimetric anions sensor bearing phenol -OH and -NH groups was synthesized. The binding properties of the receptor with anions such as F^-, Cl^-, Br^-, I^-, CH₃COO^-, H₂PO₄^-, HSO₄^-, ClO₄^-, CN^-, SCN^-, SO^2-₄ and NO^-₃ were examined by UV-Vis and ¹H NMR spectra. Upon the addition of CN^-anions, the sensor displayed apparent color changes from colorless to yellow while other anions did not cause obvious color changes. The UV-Vis spectroscopic titration experiments and MS data indicated the formation of 1: 1 addition compound between CN^- and the sensor. The results showed that the sensor in DMSO/H₂O(volume ratio 5: 5) solution indicated colorimetric single selectivity for CN^- which could be observed by naked eyes due to the nucleophilic addition reaction of cyanide.

Key words: Cyanide recognition, Anion recognition, Colorimetric detection, Azosalicylic aldehyde, Nucleophilic addition