通过7-二甲氨基香豆素.3-醛和碘化1,2-二甲基吡啶季盐的缩合反应合成了一种半菁染料。在纯水体系中,半菁染料以吸收波长蓝移和荧光淬灭双重传感高选择性地识别氰离子。双重传感效应归因于氰离子对半菁染料的麦克尔体系的亲核加成引起的共轭链的断裂,中断了香豆素和吡啶季盐结构单元间的分子内电荷转移。
A hemicyanine dye has been prepared through cross-coupling reaction of 7-diethylaminocoumarin-3-carbalde- hyde and 1,2-dimethylpyridinium. Hemicyanine dye showed high selectivity for cyanide over other anions by dual changes in both maxima absorption (blue-shift) and emission (turn- off) bands in the water.