Synthesis, kinetics and thermodynamic properties of N,N′-di(antipyrine-4-yl) oxalamide for the detection of Cu2+ ions as a selective colorimetric chemosensor

A novel antipyrine-based N,N'-di(antipyrine-4-yl) oxalamide (DAO), which exhibits selective colorimetric chemosensor properties for Cu2+ ions, was synthesized in a single-step and characterized using NMR, FT-IR, Mass spectrometry, and UV-Vis spectroscopy. In this study, a fast and effective colorimetric assay was developed for naked-eye detection of Cu2+ ions and a detection limit of 0.42 mu M. In addition, the potential application of DAO was expanded for the detection of Cu2+ ions with functional recovery in both natural and simulated water samples. The thermodynamic (Delta G(o), Delta H-o, and Delta S-o) and kinetic (E-a) parameters were investigated at four temperatures. The kinetic study showed that the colorimetric chemosensor reacted with Cu2+ ions in accordance with the second-order model. In addition, the binding constant of DAO, which binds with Cu2+ ions according to 1:1 stoichiometry, was calculated as 2.63 x 10(3) M-1. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

A novel antipyrine-based compound DAO with selective colorimetric chemosensor properties for Cu2+ ions was synthesized and characterized. A fast and effective colorimetric assay for naked-eye detection of Cu2+ ions was developed with a detection limit of 0.42 uM. DAO showed potential application for the detection of Cu2+ ions in natural and simulated water samples, and the binding constant with Cu2+ ions was calculated as 2.63 x 10(3) M-1.