Theoretical studies of three triazole derivatives as corrosion inhibitors for mild steel in acidic medium

Corrosion inhibitive performance of 4-chloro-acetophenone-O-1'-(1'.3'.4'-triazolyl)-metheneoxime (CATM), 4-fluoro-acetophenone-O-1'-(1'.3'.4'-triazolyl)-metheneoxime (FATM), and 3,4-dichloro-acetophenone-O-1'41'.3'.4'-triazolyl)-metheneoxime (DATM) during the acidic corrosion of mild steel surface was investigated using density functional theory (DFT). Quantum chemical parameters such as the highest occupied molecular orbital energy (E-HOMO), the lowest unoccupied molecular orbital energy (E-LUMO), energy gap (Delta E), Mulliken charges, hardness (xi), dipole moment (mu), and the fraction of electrons transferred (Delta N), were calculated. Quantitative structure activity relationship (QSAR) approach has been used, and a composite index of above-mentioned descriptors was performed to characterize the inhibition performance of the studied molecules. Furthermore, Monte Carlo simulation studies were applied to search for the best configurational space of iron/triazole derivative system. (C) 2014 Elsevier Ltd. All rights reserved.