Md. Amin Hasan, N. Kumari, Pankaj Kumar
Feb 13, 2013
Citations
0
Influential Citations
3
Citations
Journal
Polyhedron
Abstract
Abstract Azo–enol based ligands 2-[N′-(1-acetyl-2-oxo-propylidene) hydrazino]-benzoic acid (L1H2) and 4-[N′-(1 acetyl-2 oxo-propylidene)-hydrazino]-benzoic acid (L2H2) and their complexes [Zn(L1H)2(bpy)] (1) and [Zn(L2H)2(bpy)] (2) (where bpy = 2, 2′-bipyridine) have been synthesized and characterized using elemental analyses, spectral (FT-IR, 1H NMR, 13C NMR, electronic absorption), emission and single-crystal X-ray diffraction studies. Complexes 1 and 2 display selective chromogenic and fluorogenic responses with Ag+ ions in the presence of several other metal ions. The binding is monitored separately using UV–Vis, fluorescence and 1H NMR spectral titrations. Job’s plot supports a 1:2 stoichiometry for 1 and 2 with Ag+ ions. The pH dependent “on–off” switching of fluorescence from complexes 1 and 2 have been studied. The fluorescence intensity quenches (turns-off) upon addition of OH− ions, while it enhances (turns-on) in the presence of H+ ions.