Abstract
The corrosion inhibition of mild steel in molar HCl by two newly synthesized benzodiazepine derivatives, namely: 10-benzyl-pyrrolo[2,1-c][1,4]benzodiazepine-5,11-dione (BZD=2O), and 10- benzyl-pyrrolo[2,1c][1,4]benzodiazepine-5,11-dithione (BZD=2S); has been investigated at 308 K using electrochemical and weight loss measurements. The results showed that these compounds were good inhibitors and the inhibiting efficiency increased with rise concentration of the studied inhibitors. Compound BZD=2S showed better protection properties even at higher temperatures. BZD=2S was adsorbed on the mild steel surface according to a Langmuir isotherm adsorption model. The associated kinetic and thermodynamic parameters for both metal dissolution and inhibition processes have been determined and discussed.