Synthesis, characterizations, crystal structure, inhibition effects and theoretical study of novel Schiff base on the corrosion of carbon steel in 1 M HCl

A novel Schiff base 2, 4-Bis (2-hydroxy naphthaldehyde) diiminotholuene (L), was prepared and characterized by the analysis techniques: FT-IR, UV-Vis,H-1 and C-13 NMR. X-Ray Diffraction (XRD), showing that the L was crystallized in phenol-imine form. The corrosion inhibition of carbon steel in 1 M hydrochloric acid solutions of ligand L was studied using chemical (weight loss) and electrochemical (potentiodynamic and electrochemical impedance spectroscopy (EIS)) measurements, these measurements show that the inhibition efficiency obtained by this compound increased by increasing the concentration of L. The polarization studies show that this L acts as mixed type inhibitor. This inhibitor functions through adsorption following Langmuir isotherm. The UV-Vis absorption spectroscopy was used to investigate the forming of complex between inhibitor L and Fe. The scanning electron microscopy (SEM) studies the metal surfaces confirming the formation of the adsorbed layer of inhibitor, which slows down the corrosion process in the corrosive solution. The Density functional theory (DFT) and Simulations of the Molecular Dynamics (SMD) were used to determine the relationship between quantum chemical parameters and their inhibition efficiencies, and the correlation between theoretical and experimental results was discussed.(C) 2022 Published by Elsevier B.V.

Automated summary

A novel Schiff base compound was synthesized and characterized using various analysis techniques. The compound exhibited excellent corrosion inhibition properties on carbon steel in hydrochloric acid solutions, with the inhibition efficiency increasing with the concentration of the compound. Further studies revealed that the compound acted as a mixed-type inhibitor through adsorption, following Langmuir isotherm. In addition, the formation of an adsorbed layer of the inhibitor was confirmed by UV-Vis absorption spectroscopy and scanning electron microscopy, and the correlation between theoretical calculations and experimental results was discussed.