Corrosion Inhibition Potential of Thiosemicarbazide Derivatives on ALuminium: Insight from Molecular Modelling and QSARs Approaches

Abstract

The potentials of six thiosemicarbazide derivatives towards corrosion inhibition were investigated theoretically using density functional theory (DFT) and quantitative structural-activity relationships (QSARs) methods. Their performance as corrosion inhibitors were evaluated using their calculated quantum chemical parameters such as molecular weight, softness, electronegativity, dipole moments, hardness, bandgap energy ( E), highest occupied molecular orbital energy (EHOMO), and the lowest unoccupied molecular orbital energy (ELUMO). Regression analysis was carried out using the ordinary least square method to develop a model that establishes the relationship between chemical parameters and inhibition e ciencies that have been measured experimentally. According to the results, quantum chemical parameters confirm the inhibition potential of TSC5 tobegreater than TSC2, while the predicted inhibition e ciencies of the studied thiosemicarbazide derivatives correspond to experimentally reported values with a root mean square error (%) of 1.116 and correlation coe cient of 0.998. The high correlation demonstrates and validates the quantum chemical approach’s reliability in studying corrosion inhibition on a metal surface. The validation of the developed model internally and externally demonstrates that it is robust and stable, with high predictability.