EXPERIMENTAL AND COMPUTATIONAL STUDY OF SOME IMIDAZOLE DERIVATIVES AS CORROSION INHIBITORS FOR COPPER IN SULFURIC ACID MEDIUM

Corrosion behavior of copper in 1.0 M Sulfuric acid containing either Imidazole (IM), 2 - Met hylimidazole (MIM) or Benzimidazole (BIM) was investigated experimentally via weight loss measurements and UV - Spectroscopy. The density functional theory (DFT) at the B3LYP/6 - 31G+ (2d, p) basis set level in gas phase is also applied here for theoretical st udy. Some quantum chemical parameters and the Mulliken charge densities on the optimized structures for imidazole compounds were determined. All theoretical results and experimental inhibition efficiencies of inhibitors were subjected to correlation analys es. Results obtained reveal that BIM is the best inhibitor and the inhibition efficiency (E W %) follows the sequence: BIM >MIM > IM. The adsorption behavior of BIM followed Langmuir’s isotherm. Cu(I) − BIM complex formation was confirmed by UV spectroscopy.