SPECTROSCOPIC CHARACTERIZATION AND MOLECULAR MODELING OF BIOACTIVE PYRIDINE CARBOXYAMIDE COMPLEXES

The carboxyamide ligand N, N’-bis(2-carboxy-1-oxopropanyl) pyridine 2,6- diamine (L) and its Co(II), Ni(II) and Cu(II) complexes have been prepared and characterized by spectroscopic(Electronic, IR,1H-NMR,TOF-Mass, EPR), magnetic, electrochemistry, powder XRD, molecular modeling and biological studies. Infrared spectral data indicates metal ion coordinates with the carboxyamide ligand through amide and carboxylate oxygen. The TOF mass spectrum gives an impression of the successive degradation of the desired compound with the series of peaks corresponding to the various fragments. Electronic spectra and magnetic susceptibility measurements for complexes are consistent with the square based geometry. The electron paramagnetic resonance of the Cu(II) complex shows g║ > g⊥ > 2.03, explained that unpaired electron mainly reside in the dx2-y2 ground state, further supports square planar geometry. The voltammogram of the Ni(II) and Cu(II) complex shows a quasi-reversible redox process and a simply one electron process assignable to the Ni(II)/Ni(III) and Cu(II)/Cu(I) couple respectively. Powder x-ray diffraction data helps to determine the crystal system and space group of the complexes. Molecular structure of the complexes has been optimized by molecular modeling that theoretically supports geometry of the complexes. The antibacterial activities of the compounds were tested against the Streptococcus, Staph, Staphylococcus aureus and Escherchia coli bacteria to evaluate their anti-microbial potential.