Theoretical Evaluation of Six Indazole Derivatives as Corrosion Inhibitors Based on DFT

Corrosion inhibition properties of some indazole derivatives namely, 4-fluoro-1H-indazole (compound 1), 4-chloro-1H-indazole (compound 2), 4-bromo-1H-indazole (compound 3), 4-metil-1H-indazole (compound 4), 4-amino-1H-indazole (compound 5), 4-hidroksi-1H-indazole (compound 6) were investigated by quantum chemical calculations. Al quantum chemical calculations related to these indazoles at the B3LYP / 6-31G++(d,p) HF / 6-31G++(d,p) methods were performed. Global reactivity parameters such as EHOMO, ELUMO, HOMO–LUMO energy gap (∆E), chemical hardness, softness, electronegativity, proton affinity, electrophilicity and nucleophilicity have been calculated and discussed.