Abstract:

The quantitative structure-activity relationship (QSAR) of undecyl imidazoline corrosion inhibitors for anti-corrosion behavior towards hydrogen sulfide and carbon dioxide was studied using density functional theory (DFT) and regression analysis methods. A stepwise regression analysis was used to determine the main independent factors that affected the activity of the compounds and a QSAR model was established. The stability and predictive ability of the model were examined by“leave-one-out”(LOO) cross-validation method. We found that the electron transfer parameter (△N), the electrostatic charge of non-hydrogen atoms in the imidazole ring (∑Qring) and the mean molecular polarizability (α) were the main independent factors that contributed to corrosion inhibition. The fitting correlation coefficient (R2) and the cross-validation coefficient (q2) values were 0.924 and 0.917, respectively. These values indicate that the model is of significant statistical quality and has an excellent predictive ability for corrosion inhibitors. Based on this established model, new molecules with high anti-corrosion properties for hydrogen sulfide and carbon dioxide were theoretically designed. This model may be used as a theoretical reference for the design of new corrosion inhibitors.

Key words: Corrosion inhibition performance, Imidazoline derivative, Quantumchemistry parameter, Quantitative structure-vity relationship, Molecular design