Spectroscopic, thermal and antibacterial studies on Mn(II) and Co(II) complexes derived from thiosemicarbazone

Mn(II) and Co(II) complexes having the general composition [M(L)(2)X-2] (where L = 2-pyridinecarboxaldehyde thiosemicarbazone, M = Mn(II) and Co(II), X = Cl- and NO3-) were synthesized. All the metal complexes were characterized by elemental analysis, molar conductance, magnetic susceptibility measurements, mass, IR, EPR, electronic spectral studies and thermogravimetric analysis (TG). Based on the spectral studies, an octahedral geometry was assigned for all the complexes. Thermal studies of the compounds suggest that the complexes are more stable than the free ligand. This fact was supported by the kinetic parameters calculated using the Horowitz-Metzger (H-M) and Coats-Redfern (C-R) equations. The antibacterial properties of the ligand and its metal complexes were also examined and it was observed that the complexes are more potent bactericides than the free ligand.