Abstract

In this work, chemical mechanic synthesis of six imines is reported, chemical structure and optical char- acterization is described. The imines 3a-3f were evaluated as colorimetric chemical sensors of metals: Ba^{2 +}, Co^{2 +}, Fe^{2 +}, Mg^{2 +}, Ni^{2 +}, Pb^{2 +}, Zn^{2 +}, Cd^{2 +}, Hg^{2 +}, Cu^{2 +}, Sn^{2 +} and Cs⁺ where 3e being a highly se- lective colorimetric chemical sensor for Cu^{2 +} . The limit detection of the sensor was determined through the titration, which turned out to be 4.9 × 10⁻⁶ M with a Ka of 8.264 × 10³ M⁻¹ . Also, the interference of detection in a mixture of metals was studied. Finally, by the use of IR, NMR, and DFT calculations, the structure of the 3e + M complex formed, and the phenomenon responsible for the color change was determined. Finally, a possible relationship between the selectivity to metal ions and the HOMO energy levels of the molecules is proposed, being a basis for the design of smart organic sensors

Synthesis and physicochemical characterization of Schiffbases used as optical sensor for metals detection in water