Synthesis, Characterization and Antimicrobial Evaluation Of Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) Complexes of Pyridine -2- Carboxylic Acid.

Metal (II) complexes of pyridine -2- carboxylic acid, [M (C6H4NO2)2 (H2O)] (M=Mn, Co, Ni, Cu, Zn; x=1 or 2) have been synthesized. The complexes with are air stable and molecular have been characterized by elemental analyses, conductance, IR and visible spectroscopy and room temperature magnetic susceptibility measurements. The results suggest octahedral coordination (Mn, Co, Ni, Cu, Zn) and square pyramidal structures (Cu) in which the picolinate ion is a bidentate N-and O-donor ligand. These structures have been confirmed by single X-ray crystallography for Co(II), Ni(II),and Cu(II) complexes. Thermal studies showed significant mass loss corresponding to the lost of uncoordinated and coordinated water molecules as well picolinate ions. Antimicrobial studies on nine bacterial and four fungal species reveal that the ligand and metal salts have selective activity on the bacterial species and no activity on the fungal species. The manganese and copper zinc complexes exhibited activity on S.aureus while the cobalt complex showed activity against K.pneumonia.