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

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.