Synthesis, characterization and anti-corrosion screening of co(II) thiacetazone complex / Ruqaiyah Mohamad

Co(TAC)2(NO3)2 is obtained by condensation method and have been characterized by elemental analysis (CHNS), molar conductivity, gravimetric analysis, FT-IR and UV- visible. The results of the elemental analysis are in a good agreement with the theoretical values. The melting point of complex is 247- 250 °C which is higher than ligand due to stability of complex structure. The FT- IR spectrum data was shown that the complex have coordination of bidentate form which the TAC is coordinated to Co(II) through azomethine nitrogen and thione. The shifting of wavenumber of v(C=N) and v(C=S) group are positive shift from ligand to complex. The UV-Visible analysis showed two types of transitions which are n -> TT * and rr -> TT * transitions for ligand and complex. The shifting of the absorption peak of ligand proved the coordination with Co(II) ion. The UV- Vis spectra of Co(II) complex show d-d transition that presence at wavelength >400 nm. The molar conductivity is showed that Co(II) complex is non-electrolyte and in neutral form with molecular formula of Co(TAC)2(NO3)2 The gravimetric analysis is showed the percentage of Co(II) was 7.24 % and is in a good agreement with the calculate value. For anti-corrosion screening, the inhibition efficiency of the ligand and complex are showed a good percentage in 1 M H2SO4 compared to 1 M HCl. The data shows that inhibitor efficiency is increase as the inhibitor concentration increase due to adsorption of heteroatom group on the metal surface