Synthesis, characterization, corrosion inhibition performance and mechanistic insight of tridentate hydrazone ligands on mild steel in CO₂-saturated 3.5% NaC1 solution

Corrosion of mild steel in CO₂-saturated environment poses a significant problem in the petroleum industry, where conventional inhibitors often raise environmental and sustainability concerns. In response to the growing demand for affordable and eco-friendly anti-corrosion agents, this study focuses on the development of sustainable tridentate hydrazone ligands as potential corrosion inhibitors. Four ligands (AL01-AL04) derived from benzohydrazide and 2-hydroxybenzohydrazide were successfully synthesized and characterized using melting point, FTIR, NMR, elemental analysis, UV-Vis, and mass spectroscopy. Spectroscopic data confirmed the presence of characteristic v(C=N) and azomethine proton signals (N=CH) in all synthesized compounds, indicate the successful formation of hydrazone ligands. Single crystal X-ray diffraction further supported the proposed structure for AL03 and AL04.