Herein, we present a comparative study of experimental and theoretical results on the inhibition of mild steel corrosion in hydrochloric acid using two novel pyridine Schiff base derivatives.

The corrosion inhibition properties of a pyridine derivative with more than one pyridine ring, 4-amino-N,N-di-(2-pyridylmethyl)-aniline, on mild steel in 1.0 M hydrochloric acid were estimated by potentiodynamic polarization, electrochemical impedance spectroscopy and surface analysis methods. The results showed that 4-amino-N,N-di-(2-pyridylmethyl)-aniline was a mixed type inhibitor and the inhibition efficiency decreased with the rise in temperature. The adsorption process followed the Langmuir adsorption isotherm. The thermodynamic parameters responsible for the adsorption process were also discussed. Quantum chemical calculations were performed to correlate electronic structure parameters of 4-amino-N,N-di-(2-pyridylmethyl)-aniline with its inhibition performance. Molecular dynamics simulations were also used to investigate the equilibrium configurations of 4-amino-N,N-di-(2-pyridylmethyl)-aniline on the iron surface.