Naked-Eye Detection of Anions in Dichloromethane: Colorimetric Anion Sensors Based on Calix[4]pyrrole

Abstract

The dramatic and distinctive color changes induced upon the addition of fluoride, chloride, or dihydrogen phosphate ions (A−) to solutions of calix[4]pyrroles bearing anthraquinone moieties attached through a conjugating ethyndiyl linker (see picture) in dichloromethane allow the presence of these anionic substrates to be determined by simple visual means.