Chemistry of the interaction between azole type corrosion inhibitor molecules and metal surfaces

The roles of mercapto, benzene and methyl groups in the corrosion inhibition of imidazoles on copper: I. Experimental characterization

“…According to DFT calculations [47][48][49], imidazole and benzimidazole (in neutral form) weakly chemisorb via pyridine N atom onto Cu(111) by about half an eV; benzimidazole also physisorbs nearly paralle to the surface with the adsorption energy of 0.8 eV [48]. Mercaptosubstituted (benz)imidazoles bind via the S atom or the pyridine-N and S simultaneously [5,49].…”

Effect of optimized structure and electronic properties of some benzimidazole derivatives on corrosion inhibition of mild steel in hydrochloric acid medium: Electrochemical and theoretical studies

“…These include the presence of lone pair of electrons on heterocyclic atoms, chain length (i.e., molecular volume), presence of unsaturated bond, aromatic substituent group, planarity of heterocycles, steric factor, HOMO-LUMO energy gap of the molecules, and other molecular parameters. [1][2][3][4][5][6][7][8][9][10][11][12] Several classes of N-heterocyclic compounds including benzimidazole (BI) and its derivatives have drawn considerable attention as acid corrosion inhibitors, mainly due to their significant corrosion inhibition efficiency, good chelating ability, relatively higher solubility in acid media and also their environment-friendly properties. 13 In the present study, we have used four different benzenesulphonamido and benzamido derivatives of BI (table 1) to investigate their corrosion inhibitory properties for mild steel in 1 M HCl.…”

Effect of Mercapto and Methyl Groups on the Efficiency of Imidazole and Benzimidazole-based Inhibitors of Iron Corrosion

“…The bottom layer was constrained to the bulk positions and the in-plane lattice spacing was fixed to the calculated equilibrium Fe bulk lattice parameter of 2.84 Å. 11,23 All other degrees of freedom were relaxed. Molecules were adsorbed on one side of the slab and the thickness of the vacuum region-the distance between the top of the ad-molecule and the adjacent slab-was set to about 20 Å. Molecular adsorption was modeled at 1/20 ML monolayer (ML) coverage using the (…”

“…As a starting point and for the sake of comparison with previous publications of ours 2,[11][12][13][14] and those of others, 15,16 where the bonding of imidazoles with bare metal surfaces was characterized, we choose to elucidate the bonding of the current inhibitor molecules with the bare Fe(110), although the oxidized surface of iron is way more relevant in the context of corrosion under near-neutral pH conditions. Current calculations are therefore more relevant for the reduced patches at the surface, where the oxide film has been breached.…”