Synthesis, characterization and anti-corrosion screening of zn(II) thiacetazone complex / Siti Aisyah Musa

Reaction between 4-formylacetanilidethiosemicarbazone with ZnCb in acetonitrile were produced 4-formylacetanilidethiosemicarbazone Zinc(II) chloride, [Zn(TAC)]CI with ratio 1: l(ligand:metal). The synthesized complex were characterized by elemental analysis (C, H, N and S), FT-IR, UV-Visible, molar conductance, gravimetric analysis and melting point. The shifting in infrared spectra and electronic transition showed that the ligand coordinated to metal ion through azomethine N, carbonyl O and sulfur thus produced tridentate manner of complex. The stretching of v(C=S) in the spectrum of the ligand is shifted in the spectrum of complex indicating that the sulfur atom involve in the complexation. The elemental analysis along with the molar conductance confirmed the 1: 1 electrolyte behavior of the complex, thus producing chemical formula [Zn(TAC)]Cl with percentage yield 86.34 %. For gravimetric analysis, the product formed was metal oxide, ZnO with the percentage calculated of Zn(II) in the complex was 13. 66 %. The solid residue of ZnO was formed after the decomposition was completed. The corrosion inhibitors efficiency of ligand and its metal complex in 1 M H2SO4 and 1 M HCl were determined by using weight loss method. The 0.1 M concentration of the inhibitors portrayed the good inhibition efficiency. The result showed that [Zn(TAC)]Cl has better inhibitory action against corrosion of mild steel compare to ligand.