The corrosion inhibition effect of a pyridine derivative for low carbon steel in 1 M HCl medium: Complemented with antibacterial studies

A pyridine derivative 4-chloro-2-((pyridin-2-ylimino)methyl)phenol (CPP) was synthesized and its anti-corrosion effect toward low carbon steel in 1 M hydrochloric acid medium was studied by mass loss measurements. The protective efficiency of CPP increased along with the inhibitor concentration. The effect of temperature on the corrosion performance of low carbon steel was studied in the temperature range of 303-333 K. The inhibition efficiency of CPP decreased with an increase in temperature. Experimental findings from weight loss measurements confirmed that the anti-corrosion efficiency of CPP was significant. The adsorption of inhibitor molecules on low carbon steel surface obeyed the Langmuir adsorption isotherm model. Moreover, quantum chemical calculations were conducted based on density functional theory (DFT) in order to study the relationship of inhibition efficiency and the structure of the inhibitor molecule. The quantum chemical parameters such as E-HOMO, E-LUMO, the energy gap (E), electron affinity (A), ionization potential (I), softness (S), hardness (eta), absolute electronegativity (chi), and the fraction of electron transferred (N), were determined. The antibacterial efficiency against selected types of bacteria, namely Escherichia coli and Staphylococcus aureus, was also studied. The results show that CPP has a significant potential to inhibit the growth of gram negative and gram positive bacteria.