Spectroscopic and Antimicrobial Studies of Transition Metal Complexes of a Schiff Base Macrocyclic Ligand

Cr(III) and Mn(II) complexes of a Schiff base macrocyclic ligand viz. 1,3,7,9-tetraaza-4,6,10,12-tetraphenyl-2,8-dithiacyclododecane (L) were characterized by elemental analysis, molar conductance measurements, magnetic susceptibility measurements, mass, 1H NMR, IR, electronic and EPR spectral studies. An octahedral geometry is suggested for Cr(III) and Mn(II) complexes on the basis of various spectral studies. The ligand and its complexes were evaluated in vitro for antifungal activity against three plant pathogenic fungi namely, Aspergillus niger, Aspergillus glaucus, and Aspergillus flavus and antibacterial activity against two pathogenic bacteria namely, Sarcina lutea (Gram-positive) and Escherchia coli (Gram-negative). The studied complexes exhibit mild antifungal and antibacterial activity against these organisms.