ISSN 2995-9246
International Journal of Chemistry | Vol. 1, No. 9, September 2010 | pp. 70–77
DOI: 10.46882/2010/IJC/000009
Article Type: Original Research Paper
Title: Computational Density Functional Theory (DFT) Insights into the Corrosion Inhibition Efficacy of Imidazole Derivatives on Al(111) Surface
Names of Authors: Razaq A. Balogun¹, Fatma Al-Marzouqi²
Authors’ Affiliations:
¹Department of Chemistry, University of Ilorin, Ilorin, Nigeria
²Department of Chemistry, United Arab Emirates University, Al Ain, UAE
Abstract: Quantum chemical calculations based on density functional theory (DFT) were applied to model the structural, electronic, and corrosion inhibition characteristics of three imidazole derivatives: 2-methylimidazole (2-MI), 2-phenylimidazole (2-PI), and 2-mercaptoimidazole (2-MeI) on an Aluminum (111) surface. The electronic configurations of the inhibitor molecules were optimized at the B3LYP fractional level using the 6-311G(d,p) basis set. Key global quantum chemical parameters were computed, including the highest occupied molecular orbital energy (EHOMO), lowest unoccupied molecular orbital energy (ELUMO), energy gap (Delta E), dipole moment (mu), electronegativity (chi), global hardness (eta), and the fraction of electrons transferred from the inhibitor molecule to the metal surface (Delta N). The calculations demonstrated that 2-MeI exhibited the highest EHOMO (-5.42 eV) and the lowest energy gap (3.12 eV), pointing to its high reactivity and capacity to readily donate lone pair electrons to the vacant d-orbitals of aluminum. Local reactivity trends were evaluated utilizing Fukui functions (f⁺ and f⁻) to identify the specific nucleophilic and electrophilic adsorption active sites within each compound. Molecular dynamics (MD) simulations were executed to model the configurations of the compounds on the Al(111) surface. The binding energies increased in the order of 2-MI < 2-PI < 2-MeI, agreeing with empirical weight loss metrics.
Keywords: Density Functional Theory, Corrosion inhibition, Imidazole, Quantum chemical parameters, Molecular dynamics, Fukui functions
Manuscript Timeline: Received: June 05, 2010; Revised: July 19, 2010; Accepted: August 10, 2010; Published: September 02, 2010