Synthesis and characterization of novel Cu (II) and Zn (II) complexes of 5-{[(2-Hydroxyethyl) sulfanyl] methyl}-8-hydroxyquinoline as effective acid corrosion inhibitor by experimental and computational testings

Abstract : Two new complexes were synthesized, characterized and tested as inhibitors for mild steel corrosion in 1.0 M HCl. The anticorrosive effect has been studied using the potentiodynamic polarization (PDP) and impedance spectroscopy (EIS). The inhibitory efficiency increases with increasing concentration to reach 96.0% for Q-Cu and 94.6% for Q-Zn at 10−3 M. The two inhibitors are mixed type and follows the Langmuir isotherm adsorption. The surface of the mild steel has been examined by SEM/EDS and the corrosive solution by ICP-OES. DFT calculations and molecular dynamic simulation (MD) show a good correlation with the experimental results for both complexes.