Inhibitive performance of some synthesized thiophenol derivatives on corrosion behavior of mild steel in 0.1 M HCl solution was investigated by means of electrochemical techniques, quantum chemical and optical microscopy. The increase in concentration and immersion time shows a positive effect on inhibition efficiency while temperature has a negative effect. Inhibitor molecules directly adsorb at surface on the basis of donor–acceptor interactions between the p-electrons of benzene, sulfur and nitrogen atoms and the vacant d-orbitals of iron atoms. According to the thermodynamic parameters, present inhibitors adsorb physically. Optical microscopy examinations demonstrate a decrease in corrosion attacks in presence of inhibitors.

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