Manila Journal of Science 10 (2017), pp. 44-63

Quantum Chemical Studies on Corrosion Inhibition of 1, 3-Thiazine Derivatives for Mild Steel in Acidic Media: DFT Approach

Abstract

Quantum chemical calculations via B3LYP/631G(d.p) level were performed on 1,3-Thiazine derivatives used as corrosion inhibitors for mild steel in acidic media. The calculated molecular properties such as the highest occupied molecular orbital energy (EHOMO), Lowest unoccupied molecular orbital (ELUMO), chemical hardness (ŋ), energy band gap (Eg), dipole moment, electronegativity (χ), fraction of electron transfer (ΔN), and global nucleophillicity index (ω) were correlated to the observed corrosion efficiency. The local reactivity indices were analyzed through Fukui functions in other to compare the possible sites for nucleophilic and electrophilic attacks during adsorption of the inhibitors on metal surface. The protonation of the molecular species of the studied thiazines was examined and analyzed.

Manila Journal Of Science 10 (2017), Pp 44-63 (1.5 MiB)