Rational Design of a Dual Chemosensor for Cyanide Anion Sensing Based on Dicyanovinyl-Substituted Benzofurazan

A dicyanovinyl-substituted benzofurazan derivative (C1) was prepared as an efficient ratiometric chemosensor for cyanide anion detection in aqueous acetonitrile solution. Mechanism studies suggested that the nucleophilic addition of cyanide to the alpha-position of the dicyanovinyl group blocked the ICT progress of C1 and induced remarkable emission and absorption shift.