DFT and Monte Carlo Analysis of the Anti-corrosion Behavior of a Series of the Purine Derivatives.

Corrosion poses significant challenges in both industrial applications and everyday life, necessitating effective corrosion control strategies to mitigate costs and enhance safety. This research investigates the anti-corrosion potentials of purine derivatives-hypoxanthine (1), xanthine (2), theophylline (3), theobromine (4), uric acid (5), and isoguanine (6)-using density functional theory (DFT) and Monte Carlo simulations. Electronic properties, including energy gaps, HOMO and LUMO energies, molecular electrostatic potential (MEP) surfaces, and global reactivity descriptors, were computed at the B3LYP/6-311 + + G(d, p) theoretical level. Monte Carlo simulations were employed to evaluate the adsorption efficacy of these compounds on Fe(110) and Cu(111) surfaces. The findings reveal significant electron charge transfer from the molecules to the metal surfaces, with uric acid (5) and isoguanine (6) exhibiting the highest inhibition efficiencies. Adsorption energy calculations indicate that compounds 3 and 4 exhibit lower adsorption energies on Fe(110), while adsorption on Cu(111) surfaces demonstrated approximately 1.5 times lower absolute values. These results highlight the potential of purine derivatives, particularly compounds 5 and 6, as effective corrosion inhibitors for metal surfaces.