Molecular dynamics and density functional theory study on the corrosion inhibition of austenitic stainless steel in hydrochloric acid by two pyrimidine compounds

Abstract

Quantum chemical calculations based on density functional theory method were performed on two pyrimidine derivatives which may be used as corrosion inhibitors for austenitic stainless steel. The quantum chemical properties of the two pyrimidine derivatives that are most relevant to their potential action as corrosion inhibitors have been calculated. To explain the inhibition performance of the pyrimidine derivatives, their local reactivities were analyzed through Fukui functions. The binding energies of the inhibitors with the surface of austenitic stainless steels were studied. A model has been suggested to calculate the approximate inhibition efficiencies of the pyrimidine derivatives. All calculations were carried out in both gas and liquid phases.

Mathematical Models Generated for the Prediction of Corrosion Inhibition Using Different Theoretical Chemistry Simulations

“…The theoretical report of Shojaie et al [ 50 ] indicated that the molecules with N atoms are preferentially protonated in acidic medium, contrary to the behaviour of compounds with S and O atoms. The researchers conducted the analysis of two pyrimidine derivatives (S and N compounds) and observed that there was a correlation between the molecular mass and the inhibition efficiency; the adsorption on the metal surface improved as the molecular mass increased.…”

“…They associated a higher number of heteroatoms in a molecule with its superior interaction capacity with a metallic surface. Atoms with the highest negative partial atomic charge interact more strongly with a metallic surface through a donor–acceptor interaction [ 50 ]. Caliskan et al [ 14 ] noticed in their experimental study of pyrimidine derivatives that these compounds work as mixed-type inhibitors, both cathodic and anodic reactions were influenced by the presence of compounds in the corrosive medium, being the anodic effect the most significant behaviour.…”

Synthesis, characterization and theoretical studies of novel pyrimidine derivatives as potential corrosion inhibitors

“…A mixture of 5 11 (1 mmol), benzaldehyde (1 mmol) and anhydrous sodium acetate (1 mmol) in glacial acetic acid (10 ml) was heated under reflux for 4 h. The reaction mixture was kept overnight and the solid, thus separated, was filtered, washed with water and recrystallized from ethanol. (8). The 4-(6-benzoyl-3-oxo-7-phenyl-2,3-dihydro-5H-thiazolo-[3,2-a]pyrimidin-5-yl)benzoyl chloride (7) was obtained by the reaction of 5 with thionylchloride.…”

“…Very useful information can be obtained by the quantum chemical calculations to examine the corrosion inhibiting effects of organic compounds. The quantum chemical parameters all compounds such as μ, I, A, χ, η, w, S, ΔN and ΔE backdonation were calculated according to Shojaie et al 8 (Table I).…”

“…between the transmitted electron fraction index (ΔN) and the interaction between backdonations. All these values were calculated according to Shojaie et al 8…”