The inhibiting effect of Capparis Spinosa L. extract was studied for iron and copper corrosion in aqueous chloride medium using quantum chemical calculations. Analysis of the extract composition using GC/MS chromatography showed the presence of various fatty acid compounds including three main molecule which were(9Z,12Z)-octadeca-9,12-dienoic acid (A2), 8E-octadec-8-enoic acid (A1) and hexadecanoic acid (A0). The theoretical investigation were performed with DFT methods at the B3LYP/6-311G (d) and B3LYP/3-21G* basis set. The results allowed identifying the optimal geometries, the vibration frequencies, orbital borders and morphologies that the dipole moment (µ), the energy of the highest occupied molecular orbital (EHOMO) and the energy of the lowest unoccupied molecular orbital (ELUMO). In addition, the electron fraction transferred molecules (ΔN) was determined in order to understand the interaction-extracted surface. Thus, the index calculations Fukui (f -, f +) and the Quantitative Structure-Activity Relationship Modelshave been made in order to illustrate the mechanism of inhibition of this extract on iron and copper surfaces. Satisfactory theoretical correlation was observed by a proposal of a metallic surface interaction mechanism of the extract.
I. Abidli, K. Essalah, N. Souissi
Green inhibitor, DFT calculations, Fukui indices, Quantitative Structure-Activity Relationship Models