Theoretical Evaluation of Corrosion Inhibition Performance of Some Triazole Derivatives

Abstract

In this present paper, we have made an attempt to explain the adsorption mechanism and inhibition performance of two triazole derivatives, ie., 4-(benzylideneamino)-3-propyl-5-mercapto-1,2,4-triazole(BIPMT) and 4-(salicylidene amino)-3-propyl-5-mercapto-1,2,4-triazole (SIPMT), on mild steel using density functional theory (DFT) at the B3LYP/6-31G(d,p) level. Quantum chemical parameters such as EHOMO (highest occupied molecular orbital energy), ELUMO (lowest unoccupied molecular orbital energy), the energy gap(ΔE), hardness(η), Softness(S), dipole moment(μ), electron affinity(EA), ionization potential(IE), the absolute electronegativity (χ) , the fraction of electron transferred (ΔN), electrophilicity index(ω) and the back-donation (ΔE Back-donation) have been calculated. The local reactivity has been studied through the Fukui and condensed softness indices in order to predict both the reactive centres and to know the possible sites of nucleophilic and electrophilic attacks. The obtained correlations and theoretical conclusions agree well with the experimental data.