Quantum chemical evaluation of the corrosion inhibition of novel aromatic hydrazide derivatives on mild steel in hydrochloric acid

The theoretical evaluations of the corrosion inhibition efficiency of 2-(3,4,5-tri-R-benzylidene) hydrazinecarbothioamide, (R = -H, -CH3, -OCH3 and -NH2), were done using RHF and DFT-B3LYP methods with 6-31G(d) basis set in gas phase, aqueous and acidic solutions. The correlation between the molecular structures of these compounds and their theoretically predicted inhibition effects was obtained from the quantum chemical evaluations, such that the structural parameters provided insights into the possible inhibition mechanism. 2-(3,4,5-triaminebenzylidene) hydrazinecarbothioamide showed a larger tendency of adsorption through chemisorption and physisorption and thus was identified to be the best potential candidate for excellent corrosion inhibition among the studied compounds. (C) 2016 Elsevier B.V. All rights reserved.