Author(s)

Fritzgerald Kogge Bine¹, Stanley Numbonui Tasheh¹, Nyiang Kennet Nkungli²

¹Research Unit of Noxious Chemistry and Environmental Engineering, Department of Chemistry, Faculty of Science, Univer-sity of Dschang, Dschang, Cameroon.
²Department of Chemistry, Faculty of Science, The University of Bamenda, Bamenda, Cameroon.

The efficacy and mode of action of five chalcone-based imidazole derivatives as corrosion inhibitors of aluminium metal in gas-phase and acidic medium have been investigated herein via quantum chemical calculations. Dispersion-corrected DFT (DFT-D3) and time-dependent DFT (TD-DFT) calculations were performed at PBE0/def2-TZVP//PBEh-3c and CAM-B3LYP/def2- TZVP levels of theory, respectively. Conceptual DFT, the quantum theory of atoms-in-molecules (QTAIM) and local energy decomposition (LED) analyses have been performed. The LED analysis was performed at the coupled-cluster singles and doubles with perturbative triples (CCSD(T))/def2-SVP level of theory. Frontier molecular orbital energy gaps calculated using the TD-DFT method are found to lie in the range 3.574 - 4.444 eV, indicative of good adsorption and corrosion inhibition efficacies of the investigated molecules. The interactions between aluminium and the inhibitor molecules studied are found to be energetically favorable, owing to negative computed interaction energy values. Furthermore, QTAIM analysis revealed metal-carbon, metal-oxygen and metal-nitrogen interactions in the inhibitor-aluminium complexes, which are predominantly electrostatic in character, according to LED analysis results. Calculated proton affinities (PAs) have revealed the anticorrosion potentials of the investigated inhibitors in acidic medium, with a noticeable dependency on temperature within the range 273.15 - 343.15 K.

Density Functional Theory, Anticorrosion, Inhibitor-Aluminium Interactions, Quantum Theory of Atoms-in-Molecules, Local Energy Decomposition Analysis

Bine, F. , Tasheh, S. and Nkungli, N. (2021) Corrosion Inhibition of Aluminium in Gas and Acid Media by Some Chalcone-Based N-(3-Aminopropyl)Imidazoles: TD-DFT-Based FMO, Conceptual DFT, QTAIM and EDA Studies. Computational Chemistry, 9, 37-63. doi: 10.4236/cc.2021.91003.