Synthesis, spectral characterization and biological activities of Mn(II) and Co(II) complexes with benzyloxybenzaldehyde-4-phenyl-3-thiosemicarbazone

Mn(II) and Co(II) complexes of benzyloxybenzaldehyde-4-phenyl-3-thiosemicarbazone have been synthesized and characterized by the investigations of electronic and EPR spectra and X-ray diffraction. Based on the spectral studies, an octahedral geometry is assigned for the Mn(II) and Co(II) complexes. X-ray powder diffraction studies reveal that Mn(II) and Co(II) complexes have triclinic crystal lattices. The unit cell parameters of the Mn(II) complex are a = 11.0469 Å, b = 6.2096 Å, c = 7.4145 Å, α = 90.646°, β = 95.127°, γ = 104.776°, V = 489.7 Å3 and those of Co(II) complex are a = 9.3236 Å, b = 10.2410 Å, c = 7.8326 Å, α = 90.694°, β = 99.694°, γ = 100.476°, V = 724.2 Å3. When the free ligand and its metal complexes are subjected to antibacterial activity, the metal complexes are proved to be more active than the ligand. However with regard to in vitro antioxidant activity, the ligand exhibits greater antioxidant activity than its metal(II) complexes.

The ligand benzyloxybenzaldehyde-4-phenyl-3-thiosemicarbazone was synthesized and its Mn(II) and Co(II) metal complexes were prepared. The metal complexes were characterized by EPR, electronic spectra, and XRD. The free ligand and its metal complexes were subjected to antibacterial and antioxidant activity. The ligand exhibits greater antioxidant activity than its metal(II) complexes.Figure optionsDownload as PowerPoint slideResearch highlights
► X-ray powder diffraction studies reveal that Mn(II) and Co(II) complexes have triclinic crystal lattices.
► The unit cell parameters of the Mn(II) complex are a = 11.0469 Å, b = 6.2096 Å, c = 7.4145 Å, α = 90.646°, β = 95.127°, γ = 104.776°, V = 489.7 Å3 and those of Co(II) complex are a = 9.3236 Å, b = 10.2410 Å, c = 7.8326 Å, α = 90.694°, β = 99.694°, γ = 100.476°, V = 724.2 Å3.
► When the free ligand and its metal complexes are subjected to antibacterial activity, the metal complexes are proved to be more active than the ligand.
► However, with regard to in vitro antioxidant activity, the ligand exhibits greater antioxidant activity than its metal(II) complexes.