Schiff Base Ligand 3-(-(2-Hydroxyphenylimino) Methyl)-4H-Chromen-4-One as Colorimetric Sensor for Detection of Cu(2+), Fe(3+), and V(5+) in Aqueous Solutions

The ligand 3-(-(2-hydroxyphenylimino) methyl)-4H-chromen-4-one (SL) has been synthesized and examined as a chemosensor for some metal ions in aqueous solutions based on colorimetric analysis. Color changes were monitored using UV–visible spectroscopy. Binding stoichiometry and limit of detection (LOD) were estimated using titration experimentation based on UV–visible absorbance and Job's plot. The synthesized ligand was tested for selectivity in the presence of several cations and was examined for possible utility as a chemosensor in real water samples. The results indicated sensing ability and selectivity for Cu(2+), Fe(3+), and V(5+). Stable complexes were formed between SL and Cu(2+), Fe(3+), and V(5+), and the ligand-to-metal binding stoichiometry was found 2 : 1 in the SL-Cu(2+) and SL-Fe(3+) complexes, and 1 : 1 in the SL-V(5+) complex. The results of LOD and bending constant were (7.03 μM, 1.37 × 10(4) M(−1)), (5.16 μM, 2.01 × 10(4) M(−1)), and (5.94 μM, 1.82 × 10(4) M(−1)) for Cu(2+), Fe(3+), and V(5+), respectively.