Schiff Base Ligand 3-(-(2-Hydroxyphenylimino) Methyl)-4H-Chromen-4-One as Colorimetric Sensor for Detection of Cu²⁺, Fe³⁺, and V⁵⁺ in Aqueous Solutions

Figure 1

(a) UV–visible spectra of SL (1.0 × 10⁻³ M) in the presence of 1 equiv. of different metal ions (1.0 × 10⁻³ M) Cu²⁺, Cr³⁺, Fe²⁺Ni²⁺, Ca²⁺, Co²⁺, Mg²⁺, Zn²⁺, Fe³⁺, NH₄VO₃ (V⁵⁺), Mn²⁺, Hg²⁺, Pb²⁺, Ba²⁺, and Al³⁺, UV-vis. Absorption spectra of the free ligands SL (inset), (b) “naked eye” monitoring of color changes of SL (1.0 × 10⁻³ M) on adding 1 equiv. of different metal ions (1.0 × 10⁻³ M) Cu²⁺, Cr³⁺, Fe²⁺Ni²⁺, Ca²⁺, Co²⁺, Mg²⁺, Zn²⁺, Fe³⁺, NH₄VO₃ (V⁵⁺), Mn²⁺, Hg²⁺, Pb²⁺, Ba²⁺, and Al³⁺ in ethanol-H₂O solvent mixture (9 : 1, v/v).

(a)

(b)