Quantum chemical study of some triazoles as inhibitors of corrosion of copper in acid media

The efficiency of 1H-1,2,4-triazol-3-amine (Tz1), 4-amino-3-hydrazino-4H-1,2,4-triazole-3-thiol (Tz2), and 1H-1,2,4-triazole-3,5-diamine (Tz3) as inhibitors of corrosion of copper in nitric acid was investigated by use of density functional theory (DFT). Quantum chemical data, for example energy of the highest occupied molecular orbital (E (HOMO)), energy of the lowest unoccupied molecular orbital (E (LUMO)), energy gap (Delta E), dipole moment (mu), electronegativity (chi), electron affinity (A), global hardness (eta), softness (sigma), ionization potential (I), fraction of electrons transferred from the inhibitor molecules to the metallic atom (Delta N), and total energy (TE), were calculated. All calculations were performed by use of DFT with Gaussian 03W software. A good correlation was found between theoretical data and experimental results.