Hydrazine bridged coumarin-pyrimidine conjugate as a highly selective and sensitive Zn sensor: Spectroscopic unraveling of sensing mechanism with practical application.

We report the synthesis and Zn sensing of a novel coumarin-hydrazine conjugate 3-{1-[(4, 6-Dimethyl-pyrimidin-2-yl)-hydrazono]-ethyl}-chromen-2-one (3). Compound 3 can act as a neat fluorescent Zn sensor by an increment in fluorescence intensity along with an appreciable red shift. Fluorescence enhancement is caused by complexation through cis-trans isomerization process in the presence of Zn ion. The practical utility of 3 was demonstrated by successful test kit experiment to detect Zn in water under UV-light.