Potential Antimicrobial Properties of Two New Synthetic Metal Complexes Containing a Tetradentate Schiff Base

Two new Schiff base metal complexes namely [Mn(H2L)(NCS)2] (1) and[Co (H2L)(NCS)2] (2)where L= [{2, 2´-[(1E, 2E)-ethane-1,2-diylidenedi (E) azanylylidene] dibenzenethiol}], have been synthesized by reacting equimolar amounts of the respective metal perchlorate and the tetradentate Schiff base, H2L in methanol. The complexes have been characterized by spectroscopic and physicochemical studies. The antibacterial and antifungal activities of the ligand and complexes (1and 2) have been tested against some Gram positive, Gram negative bacteria and fungal strain. Manganese complex (compound 1) had higher antibacterial and antifungal effect in comparison to cobalt complex (compound 2). Again Gram positive bacteria were more susceptible to the metal complexes than the Gram negative bacteria. The metal complexes had moderate effect in human pathogenic fungus Candida albicans but stronger effect in plant pathogen Aspergillus niger. Both metal complexes had higher antimicrobial and antifungal effect than the free ligands.