New cobalt(II) tetraaza macrocyclic complexes: Synthesis, spectral and antimicrobial studies

A series of new Co-II complexes of general composition [CoLX2] (where X = Cl-, NO3-) with N-4 donor macrocyclic ligands (L) have been synthesized. The geometry of the complexes have been characterized by elemental analysis, molar conductance, thermal analysis, magnetic susceptibility measurements and spectral (electronic, IR, H-1 NMR, C-13 NMR, mass) studies. All the complexes are of high spin type showing magnetic moment corresponding to three unpaired electrons. Octahedral geometry is tentatively proposed for all the complexes. Antimicrobial activities of these complexes are also studied and thio group containing complexes found to be more active than the streptomycin and ampicillin.