Experimental, quantum chemical and molecular dynamics studies of imidazoline molecules against the corrosion of steel and quantitative structure-activity relationship analysis using the support vector machine (SVM) method

The inhibition performance of nine imidazoline molecules against the corrosion of steel in 15 wt.% HCl and 3 wt.% HF solution was studied by weight-loss method, quantum chemical calculation, molecular dynamics simulation and the quantitative structure-activity relationship (QSAR) analysis. The quantum chemical calculation involved in local reactivity suggested that the nitrogen atoms in the imidazole ring and carbon atoms in hydrophilic group were the possible active sites to be adsorbed on iron surface. The acid solution was taken into consideration in molecular dynamics simulation and the results indicated that the order of the binding energies agrees well with that of the inhibition efficiencies. The QSAR model was built by the support vector machine (SVM) approach to correlate between the inhibition efficiencies of the imidazoline molecules and their quantum chemical parameters as well as the binding energies. The QSAR model shows good performance since the value of correlation coefficient R2 was reasonably high. What's more, eight new imidazoline molecules were theoretically designed and their inhibition efficiencies were predicted by the established QSAR model.