Electrochemistry evaluation and quantum corroboration with surface analysis of potential anticorrosive of two new pyridazine derivatives for mild steel in 1 M HCl solution

Two new structurally related pyridazine derivatives, Ortho (PO) and Para (PP), were synthesized by greener chemical pathway, and were spectroscopically specified by 1H NMR and 13C NMR. Their application in corrosion inhibition of mild steel (MS) in 1.0 M HCl was explored by experimental electrochemical tests of Potentiodynamic Polarization (PDP), Electrochemical Impedance Spectroscopy (EIS), with a surface and corrosive solution analyses by means of Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX) analysis, and UV-vis spectroscopy, as well as by Density functional theory (DFT) calculations for corroboration and development of an interpretation of the experimentally obtained anticorrosive activity by referring to the particular effects of molecular structure. Electrochemical experiments tests provided that the two compounds act by physisorption and chemisorption adsorption modes, with a maximum efficiency of 94.4% and 95.4% for PO and PP, respectively at 10-3 mol L-1, and obey of Langmuir's theory of monolayer adsorption. SEM/EDX and UV-vis analysis confirmed this state of adsorption by an inhibitor film. DFT quantum chemical descriptors and molecular dynamics simulations showed a reasonable correlation with experimentally corrosion inhibition performance.

Automated summary

Two structurally related pyridazine derivatives, Ortho (PO) and Para (PP), were synthesized using an environmentally friendly chemical pathway and characterized by spectroscopic techniques. Their corrosion inhibition performance on mild steel in 1.0 M HCl was investigated through electrochemical tests, SEM/EDX and UV-vis analysis, as well as DFT calculations. The experimental results showed that both compounds exhibited high efficiency in inhibiting corrosion through physical and chemical adsorption modes, and the adsorption behavior was supported by Langmuir's theory and confirmed by SEM/EDX and UV-vis analysis. The correlation between the experimental data and DFT calculations demonstrated the potential of these compounds as corrosion inhibitors.