Understanding Inhibition of Steel Corrosion by Some Potent Triazole Derivatives of Pyrimidine through Density Functional Theory and Molecular Dynamics Simulation Studies

Abstract

Density Functional Theory (DFT) calculation at B3LYP level of theory and 6-31G* basis set wasapplied on some triazole derivatives of pyrimidine which led to the optimization of their structures,generation of electronic and other important Quantum chemical descriptors such as the energy of the highestoccupied molecular orbital (EHOMO), the energy of the lowest unoccupied molecular orbital (ELUMO), energy bandgap (ΔE), Dipole Moment (E), Dipole Moment (μ)), chemical hardness (η),), chemical softness (σ)), global electronegativityσ =1η =− 2 EHOM −E LUMO (χ) andnumber of transferred electrons (ΔE), Dipole Moment (N) using SPARTAN’14 Software. The obtained results shows a goodcorrelation between the chemical structures of the inhibitors and their experimental inhibition efficiencies(%IEs). The ranking of these efficiencies (%IEs) nicely matched with the order of a good number of thegenerated descriptors but with a varying degree of correlation as majority of the descriptors indicates that I4 is the best inhibitor among the data set. Furthermore, molecular dynamic (MD) simulations were carriedout to search the best adsorption configuration of the inhibitor on the steel (1 1 0) surface using MaterialStudio 8.0. The obtained results of MD simulations suggest that the interaction was as a results of thechemical adsorption on the steel surface, since the binding energy > 100 Kcalmol-1 for all the inhibitors andthe best adsorption energy was found to be -488.07 Kcalmol-1 (I-4). This observation are in good agreementwith the DFT results and the experiment findings. Thus; this study provides a valuable approach and newdirection to novel steel corrosion inhibitor discovery.