Synthesis, characterization and corrosion inhibition efficiency of 2-(6-methylpyridin-2-yl)-1H-imidazo[4,5-f][1,10] phenanthroline on mild steel in sulphuric acid

Abstract

Phenanthroline derivative, 2-(6-methylpyridin-2-yl)-1H-imidazo[4,5-f][1,10] phenanthroline (MIP) was synthesized and characterized by elemental analysis, FT-IR, 1H NMR, 13C NMR, and single crystal X-ray diffraction study. MIP was evaluated as corrosion inhibitor for mild steel in 0.5 M H2SO4 solution using gravimetric and UV–Visible spectrophotometric methods at 303–333 K. Results obtained show that MIP acts as inhibitor for mild steel in H2SO4 solution. The inhibition efficiency was found to increase with increase in MIP concentration but decreased with temperature. Activation parameters and Gibbs free energy for the adsorption process using statistical physics were calculated and discussed. The UV–Visible absorption spectra of the solution containing the inhibitor after the immersion of mild steel specimen indicate the formation of a MIP-Fe complex.

Keywords

• Phenanthroline derivative
• Mild steel
• Corrosion inhibitors
• Sulphuric acid
• Thermodynamic