Corrosion Inhibition Mechanism of Novel Thiosemicarbazide Derivatives and Their Copper (II) Complexes on Mild Steel in 18,230 ppm (0.5 M) HCl

نویسندگان

1 Department of Chemistry, Faculty of Science, Sebha University, Libya

2 Department of Chemistry, Faculty of Science, Sebha University, Libya

3 Department of Chemistry, Faculty of Education, University of Fezzan, Libya

4 Department of Chemistry, Faculty of Science, Sebha University, Libya

5 Department of Chemistry, Faculty of Science, Sebha University, Libya

doi
10.48309/jaoc.2026.561774.1367
چکیده

Challenge in diverse industrial applications, requiring the creation of effective and sustainable inhibitors. In this research, two thiosemicarbazide derivative ligands were synthesized through the condensation of thiosemicarbazide with diacetylmonoxime and 1-phenyl-1,4-propanedione-4-oxime. After that, these derivatives were combined with 2,3-indolinedione (isatin) to make two new SNO donor ligands (L1 and L2) in pure form and with high yields. Coordination complexes were prepared by reacting these ligands with Cu (II) ions. The structural characteristics of the synthesized ligands and their corresponding metal complexes were comprehensively elucidated using FT-IR, UV-Vis, 1H- and 13C-NMR, and mass spectrometry. Based on the spectroscopic analysis, L2 takes on the enol form in the solid state, whereas L1 exists in the thiol form. Moreover, complexes with a suggested octahedral geometry are produced by L1 acting as a tridentate ligand and L2 acting as a bidentate ligand toward the Cu (II) center. The weight loss method was used to assess the compounds' ability to inhibit corrosion in mild steel in 0.5 M HCl at room temperature. A significant inhibitory activity was shown by the results, with inhibition efficiency rising as the inhibitor concentration increased. With a maximum inhibition efficiency of 96.52 %, the efficiency was in the following order: L2 > L1 and CuL1 > CuL2. These results demonstrate the potential of these new complexes as efficient corrosion inhibitors for protecting industrial steel.