Dual channel chromo/fluorogenic chemosensors for cyanide and fluoride ions – an example of in situ acid catalysis of the Strecker reaction for cyanide ion chemodosimetry

Abstract

Two mesitylene based probes, having catechol/phenol units in conjunction to the Schiff base have been synthesized. The probe with a catechol unit can be used to sense and discriminate between F⁻ and CN⁻ through different colorimetric and fluorimetric responses using DMSO as solvent. However in DMSO : water (2 : 1) solution it responds selectively to CN⁻ ion. The probe with a phenol unit is highly selective and sensitive for CN⁻ and can be used for naked eye, semiquantitative sensing of CN⁻ ion in DMSO : water (2 : 1) solution. The chemodosimetry has been attributed to the acid catalyzed Strecker's reaction of an imine bond and is being reported for the first time in a Schiff's base.