Theoretical approach to the corrosion inhibition efficiency of some pyrimidine derivatives using DFT method of mild steel in HCl solution

H. Elmsellem, A. Aouniti, M. K

Abstract

The inhibition effect of new heterocyclic compounds, namely N-((3,5-dimethyl-1H-pyrazol-1-)methyl)pyrimidin-2- amine(Pyrm1);2-((3,5-dimethyl-1H-pyrazol-1-yl)methyl)amino) pyrimidine-4,6-diol (Pyrm2) and 2-(((3,5-dimethyl- 1H-pyrazol-1-yl)methyl)amino)-6-methylpyrimidin-4-ol(Pyrm3) on mild steel corrosion in 1 M HCl has been studied by weight loss measurements, potentiodynamic polarisation and Electrochemical Impedance Spectroscopy (EIS) measurements. The results indicated that the inhibition efficiency depends on concentration and molecular structure of the investigated compounds. It is also found that the inhibition of Pyrm2 is greater than Pyrm3 and Ppyrm1. The molecular structure effect on the corrosion inhibition efficiency was investigated using DFT calculations. The structural and electronic parameters were calculated and discussed. The obtained results show that the experimental studies agree well and confirm that Pyrm2 is the better inhibitor.