Theoretical evaluation of corrosion inhibition performance of some pyrazine derivatives

• DFT and molecular dynamics studies of pyrazine derivatives used as corrosion inhibitor.
• The correlation of inhibition effect and reactivity parameters was discussed.
• We model the interactions of some pyrazine derivatives on Fe (1 1 0) surface.
• Excellent correlation exist between inhibition efficiency and binding energy.

The adsorption properties of three pyrazine compounds namely, 2-methylpyrazine (MP), 2-aminopyrazine (AP) and 2-amino-5-bromopyrazine (ABP), for steel corrosion was investigated by quantum chemical calculation and quenched force-field molecular dynamics simulation. Global reactivity parameters such as EHOMO, ELUMO, the energy gap (ELUMO − EHOMO), dipole moment, have been calculated and discussed. Fukui indices were calculated to describe the local reactive sites of the molecules. The equilibrium adsorption behaviour of these pyrazine molecules on Fe (1 1 0) surface was investigated using molecular dynamics simulation. The binding energy followed the order: ABP > AP > MP, which is in agreement with experimental results.

Equilibrium adsorption configurations of 2-amino-5-bromopyrazine (ABP) on Fe (1 1 0) surface using molecular dynamics (MD) simulations.Figure optionsDownload as PowerPoint slide