Simple benzothiazole chemosensor for detection of cyanide anions via nucleophilic addition

A benzothiazolium salt containing carbazole group has been synthesized in a good yield via simple condensation reaction. Its photophysical properties and affinity for cyanide anion (tetrabutylammonium cyanide) have been investigated. The compound exhibited quick and well visible UV/Vis absorption and fluorescence responses to cyanide anion in MeCN, as the yellow color faded and the orange fluorescence disappeared. The in situ analysis by 1H NMR indicated that the cyanide anion was added to the C=N bond in the benzothiazolyl group.