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  μ M, 1.37 × 10 4  M -1 ), (5.16  μ M, 2.01 × 10 4  M -1 ), and (5.94  μ M, 1.82 × 10 4  M -1 ) for Cu 2+ , Fe 3+ , and V 5+ , respectively.