Mono-and Binuclear Cobalt(II) Mixed Ligand Complexes of 2,2′-Bipyridine and Ethylenediamine: Synthesis, Characterization and Biological Application

Antibiotic resistance of pathogens to the current commercially available drugs is a serious problem. To curve this problem. the discovery of active compounds with a new mode of action is insistent. In line with this we report two new complexes: mononuclear [Co(L-1)(2)(L-2)(H2O)]Cl-2 and binuclear [Co-2(L-1)(4)(L-2)(H2O)(2)]Cl-4 using precursor complex. [Co(L-1)(2)(H2O)(2)]Cl-2, synthesized before; where L-1: 2.2'-bipyridine and L-2: ethylenediamine. The precursor complex was prepared from CoCl2 center dot 6H(2)O and L-1 in ethanol, treated with a different mole of L-2 under optimized reaction conditions to give the corresponding mono-and binuclear cobalt(II) mixed ligand complexes. These complexes were characterized using the spectroscopic technique (ICP-OES, UV-Vis, FT-IR) and physicochemical methods (chloride determination, thermal analysis, and conductance measurement). Their antibacterial activities were also tested against two Gram-negative (Escherichia coli (E.coli) and Klebsiella pneumoniae (K. pneumoniae)) and two Gram-positive (Staphylococcus aureus (S. aureus), Streptococcus pyogenes (S. pyogenes)) bacteria using the disc diffusion method. The new complexes showed better activities against K. pneumoniae than the reference Gentamycin. Furthermore,[Co(L-1)(2)(L-2)(H2O)]Cl-2 demonstrated better activity than Gentamycin against S. aureus and E. coli.