Synthesis, experimental, theoretical, and molecular dynamic studies of 1-(2,5-dimethoxy-4-methylphenyl)ethan-1-thiosemicarbazone as green inhibitor for carbon steel corrosion

Abstract

In this report, a thiosemicarbazone, namely, 1-(2,5-dimethoxy-4-methylphenyl) ethan-1-thiosemicarbazone 4 was synthesized from naturally occurring paramethoxy-thymol and investigated as a new corrosion inhibitor on carbon steel in 1 M HCl solution, using combined experimental and theoretical explorations. Weight loss, potentiodynamic polarization (PDP), impedance spectroscopy (EIS), and Scanning Electron Microscopy (SEM) were used to research the inhibition performance and determine the adsorption distribution characteristics of compound 4. The obtained results revealed that this obtained molecule has a high corrosion inhibitory power for carbon steel in 1M HCl and its inhibition efficacy reaches a value of 96% at 1.5 mM compound 4. The results further revealed that compound 4 functions as an effective mixed-type inhibitor. Density function theory (DFT) and molecular dynamics simulations were also adopted to provide a robust representation of corrosion phenomena in realistic conditions. The structure synthesized was confirmed by NMR (1H & 13C), IR, and high-resolution mass spectroscopy (HRMS).