Exploration of neonicotinoids as novel corrosion inhibitors for copper in a NaCl solution: Experimental and theoretical studies

Two neonicotinoid derivatives namely 1-[(2-Chloro-5-thiazolyl)-methyl]− 4,5-dihydro-N-nitro-1H-imidazol-2-amine (IMT) and (2E)− 1-[(6-Chloro­pyridin-3-yl)­methyl]-N-nitro­imidazolidin-2-imine (IMP), are developed as copper corrosion inhibitors in a NaCl solution for the first time. The inhibition performances of two inhibitors are investigated by electrochemical measurements combined with various detailed spectral characterizations techniques. The results indicate that the maximum inhibition efficiencies of both inhibitors are greater than 97% at 298 K. The two neonicotinoid compounds can fabricate a protective film on the Cu substrate and promote a more hydrophobic surface to shield corrosive ions. Theoretical calculations reveal that IMT and IMP molecules could absorb on the Cu surface through active sites of N-nitro terminal functional groups (-N-NO2), suggesting that neonicotinoid compounds can be a reasonable alternative as corrosion inhibitors for applications in harsh industrial seawater systems.