Investigating the corrosion inhibition of copper using DFT theoretical study with three organic molecules

Abstract

A theoretical study of the inhibition efficiency of three organic heterocyclic molecules has been thoroughly probed using density functional theory B3LYP/6-31G(d) level. The calculated global quantities such as electrophilicity and nucleophilicity show that the three organic inhibitors are nucleophiles. The obtained values of charge transfer and energy of back-donation show that the 2-amino-4-(4-bromophenyl)thiophene-3-carbonitrile is the best inhibitor. Parr function indices have been calculated to determine the most preferred sites for the nucleophilic attacks towards the electrophilic transition metal surface of copper. The electrostatic surface potential has been mapped in order to explore the major regions of the molecules responsible of the inhibition. It is found that the zone surrounding the nitrogen atom and the -aromatic system of benzene are the one forming the protection layer. The theoretical results are in good commitment with the experimental results.