Electrochemical Investigation of Inhibitory of New Synthesized 3-(4-Iodophenyl)-2-Imino-2,3-Dihydrobenzo[d]Oxazol-5-yl 4-Methylbenzenesulfonate on Corrosion of Stainless Steel in Acidic Medium

3-(4-Iodophenyl)-2-imino-2,3-dihydrobenzo[d]oxazol-5-yl 4-methylbenzenesulfonate (4-IPhOXTs) was synthesized and its inhibiting action on the corrosion of stainless steel 316L (SS) in sulfuric acid was investigated by means of potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The results of the investigation show that this compound has excellent inhibiting properties for SS corrosion in sulfuric acid. Inhibition efficiency increases with increase in the concentration of the inhibitor. The adsorption of 4-IPhOXTs onto the SS surface followed the Langmuir adsorption model with the free energy of adsorption ΔG0ads of −8.45 kJ mol−1 . Quantum chemical calculations were employed to give further insight into the mechanism of inhibition action of 4-IPhOXTs. Keywords: Organic inhibitor, Adsorption, Stainless steel, Impedance, Density functional theory