Theoretical evaluation of corrosion inhibition performance of some pyrazine derivatives

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 E-HOMO, E-LUMO, the energy gap (E-LUMO - E-HOMO), 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. (C) 2014 Elsevier Ltd. All rights reserved.