Insight into the corrosion inhibition of new bis-quinolin-8-ols derivatives as highly efficient inhibitors for C35E steel in 0.5 M H2SO4

Abstract Both new bis-quinolin-8-ols, namely 5,5′ ((methylenebis(oxy))bis(methylene))bis(quinolin-8-ol)(MBQ), 5,5′-((propane-1,3-diylbis(oxy))bis(methylene))bis(quinolin-8-ol) (PBQ) were prepared in moderate yields through the O-alkylation of 5-(chloromethyl)-quinolin-8-ol hydrochloride by diol derivatives. FT-IR, elemental analysis, and NMR confirmed their molecular structures. The corrosion inhibitory potency of these new bis-quinolin-8-olswas assessed on C35E steel in 0.5 M H2SO4 electrolyte through several approaches such as weight loss, electrochemical measurements, UV–Visible spectroscopy, scanning electron microscopy (SEM) and computational techniques. All outcomes findings confirm that MBQ and PBQ considerably amended protection properties of C35E steel and their performance followed the sequence, PBQ (97.3) > MBQ (95.0) at 0.001 M. Two bis-quinolin-8-ols revealed mixed-type inhibitory activity. The EIS results are described using two the structure model in the presence of bis-quinolin-8-ols compounds. A significant reduction in corrosion attack on the samples exposed to MBQ or PBQ solution was upheld by the surface analysis. The absorption spectra of Uv–visible disclose the occurrence of high interaction between iron atoms and bis-quinolin-8-olsmolecules. The bis-quinolin-8-ols were chemisorbed on the C35E steel surface and followed the Langmuir isotherm model. To get a preferable comprehension of the adsorption of compound species on the steel interface, a detailed modeling investigation was accomplished using molecular dynamics (MD) simulation and DFT calculations.