Macrocyclic ligands are polydentate ligands containing donor atoms either incorporated or attached to cyclic backbone
and showed significance in various biological studies. Tetraaza macrocyclic complexes of transition metals, Ni(II),
Cu(II), Fe(III), and Mn(II) were synthesized in methanolic media using template method. These complexes were nonhygroscopic
and consist of crystalline solids. Structural identification of these complexes was done using analytical
techniques UV-Vis and IR Spectroscopy. The antibacterial activities of macrocyclic complexes (1-6) were screened
against both Gram-negative bacteria (Escherichia coli and Vibrio cholerae) and Gram-positive bacteria (Bacillus
subtilis and Staphylococcus aureus). In the present study we have reported that these synthesized complexes showed
slight antibacterial activity except macrocyclic complex (6) which showed moderate antibacterial activity.