Synthesis, spectral studies and bio-activity of some ligand bridged polymeric transition metal complexes of acetone p-amino acetophenone isonicotinoyl hydrazone

Ligand bridged polymeric complexes of the type [M(apainh)(H2O)X] where, M=Mn(II), Co(II), Ni(II), Cu(II), and Zn(II); X=Cl-2 or SO4; apainh=acetone p-amino acetophenone isonicotinoyl hydrazone have been synthesized and characterized. The complexes are stable solids, insoluble in common organic solvents and are non-electrolytes. Magnetic moments and electronic spectral studies suggest a spin-free octahedral geometry for all Mn(II), Co(II), Ni(II), and Cu(II) complexes. IR spectra show tridentate nature of the ligand bonding through two C=N and a C=O groups. X-ray powder diffraction parameters for some of the complexes correspond to orthorhombic and tetragonal crystal lattices. Thermal studies (TGA and DTA) of [Mn(apainh)(H2O)SO4] complex show multi-step decomposition pattern of both an endothermic and exothermic nature. ESR data of Cu(II) chloride complex in solid state show an axial spectra, whereas, Cu(II) sulfate complex is isotropic in nature. The complexes show a significant antifungal activity against a number of pathogenic fungal species and antibacterial activity against Pseudomonas sp. and Clostridium sp. The metal complexes are more active than the ligand.