Template synthesis, characterization, in vitro antimicrobial, and DNA cleavage studies of Co(II), Ni(II), Cu(II), and Zn(II) complexes with 15-membered N2O2 diazadioxa macrocycles

A novel series of 15-membered diazadioxa macrocyclic complexes [MLCl2] (M=Co(II), Ni(II), Cu(II), and Zn(II)) have been synthesized via the condensation reaction of salicylaldehyde and 1,2-dibromoethane with a 3-subtituted-4-amino-5-hydrazino-1,2,4-triazole in the presence of transition metal ions as templates in ethanol. The mode of bonding and overall geometry of the complexes have been inferred through IR, H-1 NMR, C-13 NMR, EPR, electronic spectral studies, conductivity, magnetic, thermal, and electrochemical studies. All the complexes are soluble in DMF and DMSO and are non-electrolytes. All these complexes have been screened for their antibacterial (Escherichia coli, Staphylococus aureus, Salmonella typhi, Pseudomonas aeruginosa) and antifungal activities (Aspergillus niger, Aspergillus flavus, and Cladosporium) by the minimum inhibitory concentration method. The DNA cleavage is studied by agarose gel electrophoresis. An octahedral geometry is proposed for all the complexes.