Combined DFT and Monte Carlo Simulation Studies of Potential Corrosion Inhibition Properties of Synthesis 2,4-bis(4′-n-pentyloxybenzoyloxy)-benzylidine-4″-nalkoxyaniline

Abstract

This study explores the corrosion inhibition performance of novel organic compounds (C1–C10) on the Fe (110) metal surface using density functional theory (DFT) and Monte Carlo simulations (MC). The electronic properties, including HOMO (−5.209 to −5.294 eV), LUMO (−1.458 to −1.483 eV), and energy gaps (3.734–3.811 eV), were calculated. Compounds with lower energy gaps, such as C4 (3.734 eV), exhibited higher reactivity due to enhanced electron-donating ability. Global hardness (1.867–1.906 eV) and softness (0.262–0.268 eV⁻¹) further confirmed stability trends. Electron transfer (ΔN: 1.770–1.790) and back-donation energies from (−0.467 to −0.476 eV) indicated strong inhibitor-metal interactions. Monte Carlo simulations revealed adsorption energies ranging from −143.821 to −184.859 kcal/mol, confirming spontaneous adsorption. C10 demonstrated the highest adsorption energy (−184.859 kcal/mol) indicating superior stability and inhibition efficiency. The systematic addition of ─CH3 groups influenced electronic properties and adsorption behavior, with longer alkyl chains enhancing hydrophobic protection and electron-donating effects. The dipole moment values of the studied compounds (C1–C10) increase significantly from the gas phase to the aqueous phase (DMSO) indicating enhanced polarity and improved solubility in polar solvents. This study provides insights into designing effective corrosion inhibitors and highlights the utility of computational methods in predicting their performance.