Molecular structure of synthetized hydrazinylidene based quinoxaline derivatives effect on mild steel corrosion inhibition in 1.0 HCl electrolyte: Synthesis, electrochemical and computational studies

In this paper, the anti-corrosion effect of two synthesized and characterized hydrazinylidene based quinoxaline derivatives, namely (2E,3E)-2,3-dihydrazono-1,2,3,4-tetrahydroquinoxaline (QX-F) and (2E,3E)-2,3-dihydrazono-6-methyl-1,2,3,4-tetrahydroquinoxaline (QX-N)resistance, on mild steel (MS) substrate in 1.0 M HCl medium was investigated electrochemical measurements, scanning electron microscopy (SEM) coupled with functional density theory (DFT) and molecular dynamics simulation (MD). The EIS measurements discovered that the QX-N and QX-F compounds raise the charge transfer resistance value, and reduce the double-layer capacity value, indicating the establishment of a defensive film on the MS area. In addition, the I -E curves designated that both products react as mixed-type inhibitors, and their inhibition values increase with their concentration to reach a maximum of 90.5 % and 91.8 % at 10 -3 M QX-N and QX-F, respectively. The best performance of QX-F than QX-N was attributed to the molecular structure nature. In the same way, it is founded that the investigated hydrazinylidene based quinoxaline derivatives adhere on the MS area according to the Langmuir isotherm, and they take their anti-corrosion performance at high temperature solution. These findings were confirmed by SEM analysis. Finally, the experimental results were justified and explained by the DFT calculations and the MD simulation.