Synthesis of Co(II) and Ni(II) Asymmetric Tetraazamacrocyclic Complexes and Their Electrochemical and Antimicrobial Studies

In this work, the synthesis of two asymmetric Co(II) and Ni(II) tetraazamacrocyclic complexes has been carried out by the template method. The synthesized complexes have been characterized by various analytical techniques such as elemental analysis, UV-Vis, IR, and Mass spectroscopy. The mass spectral studies of the complexes have been found to agree with theoretically calculated values. The calculated molar conductance values for the two complexes suggest a non-electrolytic nature of the complexes. A distorted octahedral geometry has been assigned to both the complexes as shown by spectral studies. Results of the electrochemical studies of the complexes through cyclic voltammetry indicate that metal centers can be differentiated by their intrinsic redox systems, viz. Co(III)/Co(II), Co(II)/Co(I) and Ni(II)/Ni(I). Moreover, antimicrobial activities of complexes have been investigated against E. coli, S. aureus, B. subtilis, and P. aeruginosa pathogens. The results of these studies indicate that both the complexes exhibit significant antimicrobial activity against the tested pathogens.