Selective colorimetric sensor for cyanide anion based on 1-hydroxyanthraquinone

The article addresses the synthesis, structure and properties of 2-benzoylamino-1-hydroxyanthraquinone (la), which can function as a selective colorimetric sensor for the cyanide anion in aqueous media. Compound la was prepared in two simple steps in good yield and its structure was confirmed by X-ray diffraction analysis. UV-Vis and NMR spectroscopy, mass spectrometry and quantum chemistry studies revealed that in MeCN-H2O mixtures (95:5, v/v), cyanide ionizes the hydroxyl group of the anthraquinone, which results in a strong bathochromic effect. The association constant of cyanide anion with la was measured to be 10(488) Md-1; the detection limit is about 0.22 mu M. The presence of a benzoylamino group at position 2 of the anthraquinone core has a stabilizing effect on the anionic form of la due to the hydrogen bonding between the amide hydrogen atom and the oxygen atom of the ionized hydroxyl group. (C) 2021 Elsevier Ltd. All rights reserved.