Chromogenic anionic chemosensors based on protonated merocyanine solvatochromic dyes in trichloromethane and in trichloromethane–water biphasic system

Three merocyanine dyes (two pyridiniophenolates and Brookerʹs merocyanine) were dissolved in trichloromethane in their protonated form, and their potential as anionic chromogenic chemosensors was explored by adding various anions. The experimental data collected were treated considering a model based on the proton transfer from the protonated dye to the anion. One of the dyes was used in the development of an anionic colorimetric assay based on a trichloromethane–water biphasic system, which was able to selectively detect cyanide among other anionic species.