Synthesis and Cation Recognition Properties of A New N-Acylhydrazone Receptor

A fluorescent chemosensor, 2-pyridylaldehyde-4-ethoxybenzoylhydrazone (PAEB), was synthesized and its structure was characterized by IR spectrometry, 1H NMR and elemental analysis. Mechanism of complexation of PAEB with various metal ions, especially the divalent cations of Zn, Cu, Pb, Co, Cd and Ni, and the fluorescence property of its complex with Zn(Ⅱ) ion in an ethanolic acetate buffer medium of pH 8.8 were studied by UV-VIS spectrophotometry and fluorophotometry. It was found that a complex of PAEB with Zn(Ⅱ) having its mole ratio of 1 to 1 was formed, and significant enhancement of fluorescence emission at 470 nm (when excited at 400 nm) with high selectivity was observed. The mechanism involved was discussed preliminarily.