The amidine based colorimetric sensor for Fe³⁺, Fe²⁺, and Cu²⁺ in aqueous medium

An amidine based chemosensor AM-1 was synthesized and characterized by various spectroscopic (FT-IR, 1H-NMR and mass) data and elemental analyses. Sensor AM-1 exhibited high selectivity and sensitivity towards Fe³⁺, Fe²⁺ and Cu²⁺ in the presence of other surveyed ions (such as Sr²⁺, Cr³⁺, Co²⁺, Ni²⁺, Zn²⁺, Ag⁺, Al³⁺, Ba²⁺, Ca²⁺, Cd²⁺, Cs⁺, Hg²⁺, K⁺, Li⁺, Mg²⁺, Mn²⁺, Na⁺ and Pb²⁺) with a distinct naked-eye detectable color change and a shift in the absorption band. Moreover, the emission of AM-1 was quenched selectively only in the presence of Fe³⁺