Template synthesis and spectral studies on mononuclear complexes of chromium(III) and manganese(II) with tetradentate N4 donor macrocycles.

The present article deals with the synthesis, spectral characterization and antimicrobial activity of a series of new complexes of chromium(III) and manganese(II)of general formula [Cr(Macn)Cl2]·Cl and [Mn(Macn)Cl2] respectively. These complexes were prepared via template reaction by mixing methanolic solution of diacetyldihydrazone, diacids (oxalic acid, succinic acid, glutaric acid and adipic acid) with CrCl3·6H2O and MnCl2·4H2O in 2:2:1 M ratios respectively. The newly synthesized complexes were characterized on the basis of chemical analysis and spectral studies like IR, UV, ESR and X-ray diffraction. An octahedral structure has been proposed for the chromium(III) and manganese(II)macrocyclic complexes. The synthesized complexes were further tested in vitro against fungi and bacteria in order to assess their antibacterial and antifungal activities. The studies demonstrate that the complexes possess antimicrobial properties.