LAUSR

Abstract The inhibition efficiency of N- and/or O-containing compounds for the corrosion of metals and alloys in aggressive media is an essential theme. For this purpose, a newly synthesized and fully characterized multidentate ligand, N,N'-((ethane-1,2-diylbis(azanediyl))bis(ethane-2,1-diyl))bis(quinoline-2-carboxamide) (QATETA), derived from quinaldic acid and triethylenetetramine (TETA) was examined gravimetrically and electrochemically as an inhibitor for the corrosion for mild steel in aqueous sodium chloride (3.5 %). Moreover, the reactivity and efficiency of QATETA were also theoretically investigated using density functional theory and Monte Carlo simulations methods. The results indicate that the corrosion inhibition of QATETA was concentration-dependent. In addition, QATETA was categorized as a mixed type inhibitor. Thermodynamic calculations confirmed that the adsorption of QATETA on the metal surface is a spontaneous process obeying Langmuir adsorption isotherm. Furthermore, computational simulations have corroborated the experimental results. Both physical and chemical adsorption mechanisms are suggested.