Novel coumarin fluorescent dyes: Synthesis, structural characterization and recognition behavior towards Cu(II) and Ni(II)

摘要

A series of novel coumarin dyes (3—12) were designed and synthesized. The structures of the dyes were characterized by IR, ~1H NMR, ~(13)C NMR, ~(19)F NMR, MS and single crystal X-ray diffraction. 3-(2-Benzoylhydrazonotrifluoroethyl)-7-(N,N-diethylamino)coumarin (11) could recognize Cu~(2+) and Ni2~(2+) selectively in aqueous solution. Upon addition of Cu~(2+) or Ni2~(2+) to 11 a blue shift or a bathochromatic shift of the absorption band was observed while the emission band blue-shifted with decrease in the fluorescence intensity. Upon addition of Cu~(2+) the color of the solution of 11 changed from orange to red. The results showed that 11 could be used as an optical chemosensor of Cu~(2+) and Ni2~(2+).