Investigation of Synthesis, Structural Characterization, Antioxidant Activities and Thermal Properties of Zn(II), Fe(II) and Mn(II) Complexes with Thiophene-Carboxylate Ligand

Condensation reactions of (E)-ethyl-2-(2-hydroxy-3-methoxybenzylideneamino)-6methyl-4,5,6-tetrahydrobenzo[b]thiophene-3-carboxylate (HL) with Zn(II), Fe(II) and Mn(II) salts provide three new metal complexes which were synthesized in solid state and characterized by elemental analyses, magnetic susceptibility, molar conductance, 1H-NMR, 13C-NMR, FT-IR, UV-Vis., mass techniques and thermo gravimetric analyses. The antioxidant properties of the Zn(II), Fe(II) and Mn(II) complexes were investigated by using different in vitro assays. Elemental and mass spectrometric data are consistent with the proposed formula. IR spectra confirm the bidentate nature of the Schiff base ligand. The electronic absorption spectral data of the complexes suggest an octahedral geometry around the central metal ion for all the complexes. Thermal studies of the complexes are also reported.