DFT computations and molecular dynamics investigations on conformers of some pyrazinamide derivatives as corrosion inhibitors for aluminum

Abstract

The corrosion inhibition performance of conformers of some selected pyrazinamide derivatives was investigated using density functional theory (DFT) and molecular dynamics simulations. Miscellaneous global and local chemical reactivity descriptors were calculated and correlated to the inhibition efficiency such as the highest occupied molecular orbital energy (HOMO), the lowest unoccupied molecular orbital energy (LUMO), the energy gap (∆Egap), ionization energy (I), electron affinity (A), dipole moment (μ), absolute hardness (η), absolute electronegativity, absolute softness (σ) and the fraction of electron transferred (ΔN). The Fukui function and local softness indices were computed for the determination of the most plausible nucleophilic and electrophilic attack sites. Overall, our results pointed out that the inhibition performance correlates well with the calculated quantum chemical parameters.The adsorption of pyrazinamide derivatives on the aluminum surface was modeled to unravel the adsorption mechanism which involves mainly established covalent AlO bonds as a determinant factor corroborating thus the observed ranking of the inhibition efficiency trend.