The inhibition mechanism of a new synthesized indole derivative for copper in acidic environment via experimental and theoretical study

The 3,3′-((4-(methylthio)phenyl)methylene)bis(1H-indole) (TPBI) of indole derivative was synthesized through the reaction of indole (ID) with 4-(methylthio)benzaldehyde. The electrochemical investigation showed that TBPI served as mixed-type inhibitor to protect copper against corrosion more efficiently than ID, which was further demonstrated by comprehensive characterizations. The efficient inhibitive performance was attributed to the self-assembled monolayers (SAMs) on the copper surface formed by the interaction of N and S atoms of TPBI with copper (I). Quantum calculations results further confirmed that the inhibitory effect of TPBI was better than ID. Keywords: Copper corrosion, Indole derivative, Self-assembled monolayers, Electrochemical experiments, Quantum calculations