Synthesis and recognition properties for copper ions and cyanide anions of two coumarin hydrazide compounds

Two coumarin hydrazide compounds were synthesized by 7-N,N-diethylaminecoumarin-3-formyl chloride and 2-pyridinecarboxylic acid hydrazide or benzoylhydrazine. The compounds are found to be able to recognize copper ions and cyanide anions accompanied by obvious UV–vis absorption change and fluorescence turn-off response. Mechanism studies suggested that complexation between compounds and copper forms and cyanide may be bonded to 4-position of coumarin.