Schiff base based colorimetric probes for the detection of cyanide and fluoride anions

The present work describes the design and synthesis of a simple azo-azomethine colorimetric chemosensors to excellent sensitivity and selectivity detect cyanide and fluoride ions over other anions. Chemical structure of the chemosensors was characterized by spectroscopic techniques. Probe 2 showed a notable color change from yellow to red upon the addition of aqueous solution of either Fˉ or CNˉ ion. The recognition details of Fˉ and CNˉ sensing were also evaluated using UV-Vis spectroscopy technique. The hydrogen bonding with these anions provides remarkable colorimetric responses.