Synthesis, crystal structure, DFT, molecular dynamics simulation and evaluation of the anticorrosion performance of a new pyrazolotriazole derivative

A new pyrazolotriazole derivative, namely, 1-acetyl-6-methyl-1H-pyrazolo [3,2-c][1,2,4]triazole (APT) was synthesized. The corrosion inhibition performance of APT on carbon steel in 1 M hydrochloric acid solution was investigated using potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) methods. The results showed that the inhibition efficiency of APT increases with concentration and attains its maximum of 93% at 10⁻³ M. The potentiodynamic polarization study suggests that APT acts as mixed type inhibitor. The EIS studies show that APT produces a covering layer at the metal/electrolyte interface. The adsorption of this compound on steel surfaces followed a Langmuir adsorption isotherm. DFT calculations at the B3LYP level of theory and the analyses of frontier orbitals allow the determination of the active adsorbed sites of APT on the metal surface, and molecular dynamics simulations further illustrate the most reasonable adsorption configuration.