A new 1,2,3-triazole-decorated imino-phenol: selective sensing of Zn2+, Cu2+ and picric acid under different experimental conditions

Abstract

A new 1,2,3-triazole-decorated imino-phenol 1 has been synthesized, characterized and employed in metal ion sensing. Compound 1 is weakly fluorescent in CH₃CN–H₂O (3 : 1, v/v, pH = 6.8, and 10 mM HEPES buffer containing 1% DMSO) and shows substantial increase in emission upon interaction with Zn²⁺ over a series of other metal ions. The binding constant (K_a) and detection limit are evaluated as 9.06 × 10⁴ M⁻¹ and 1.8 × 10⁻⁶ M, respectively. In the sensing of Zn²⁺, Cu²⁺ is observed to interfere and in reference to this, the selective sensing of Cu²⁺ is achieved by the ensemble 1.Zn²⁺ in CH₃CN–H₂O (3 : 1, v/v, pH = 6.8, and 10 mM HEPES buffer containing 1% DMSO). As an application, the zinc-ensemble has been employed to detect picric acid (PA) over a series of other nitroaromatics. The experimental findings have been explained by a theoretical study using density functional theory.