Heterocyclic Inhibitor Metal Surface Self-assembled Monolayer Qm / Md Study

The inhibiting mechanism of the corrosion inhibitors were studied by using Quantum chemical calculation and molecular dynamics, including benzotriazole(BTA) and a series of alkyl esters (methyl, butyl, hexyl, and octyl) of carboxybenzotriazole, isoquinoline and its hydroxyl and carboxylic derivates, and pyridine derivates.The reactivity of the derivates of BTA and isoquinoline in the neutral or acidic solution were analyzed through the charge distribution , contribution to frontier orbital and Fukui indices of weight atoms by means of density functional theory(DFT) calculations, at the level of B3LYP with the 6-31G* base sets; and clarified the inhibiting mechanism farther by analyzed the correlation between the inhibition efficiencies and some quantum chemical parameters, such as orbital energy, charge density of frontier orbital, charge distribution, distributive coefficient, polarizability; In addition, the CASTEP module was used to optimize the adsorption process of pyridine and its derivates on metallic crystal surfaces. Finally, the charge distribution and density of state were obtained, the interaction was clarified clearer.Molecular dynamics simulations were performed to model the combinative process of the derivates of BTA and pyridine on metallic crystal surfaces, using Discover module, NVT ensemble and Compass force field, then binding energy, theoretic sequence of inhibition efficiencies and pair correlation function were obtained to discuss the interaction and clarify the inhibiting mechanism.