Quantum chemical and experimental characterization of the effect of ziprasidone on the corrosion inhibition of steel in acid media

Ziprasidone is composed of the benzisothiozole-3-piperizine (BITP) and an indole moiety. The inhibition potential of ziprasidone for the corrosion of steel in 1.0 M HCl and 0.5 M H2SO4 was assessed by weight loss, polarisation, electrochemical impedance spectroscopy and quantum methods. The results showed that nearly 10 times lower concentration of ziprasidone showed the same efficiency that was rendered by BITP. This is related to the planarity of ziprasidone molecule, potential adsorption sites and the extensive distribution of LUMO orbitals on indole moiety which cause larger back donation. Ziprasidone follow Langmuir adsorption isotherm.

► Acid corrosion inhibition.
► Effective at very small concentration.
► The effect of indole moiety in ziprasidone towards the corrosion inhibition.
► Evaluation by quantum chemical and electrochemical methods.
► Adsorption sites, planarity and LUMO orbitals of ziprasidone.