Synthesis and spectroscopic properties of a fluorosensor for Zn2+ ions

The new Schiff base ligand L: (E)-N'-(pyridin-2-ylmethylene)acetohydrazide, was synthesized, and its reaction with Zn(II) ions form the complex: [ZnL2](ClO4)2, as confirmed by X-ray crystallography. This complex is stable in polar and non-polar solvents as proven by NMR. A significant enhancement in the fluorescence was observed from L upon coordination to Zn(II) ions over other transition metals such as Fe(II), Co(II), Ni(II), Cu(II), Cd(II) and Ag(I). These results suggest that L can be used as a selective flourosensor for the detection of Zn(II) ions.