SYNTHESIS, CHARACTERIZATION AND IN VITRO ANTIMICROBIAL STUDIES ON (2Z)-2-(2-HYDROXY-3H-INDOL-3-YLIDINEHYDRZINE-1- CARBOTHIOAMIDE AND ITS MANGANESE(II) AND IRON(II) COMPLEXES
Keywords:
Ligand Schiff base, Thiosemicarbazide, Isatin, molar conductivity, magnetic susceptibility, Empirical Formula.Abstract
Manganese (II) and Iron (II), complexes of a Schiff base obtained from condensation of Isatin
and Thiosemicarbazide were synthesized. The Schiff base and the complexes were
characterized by FTIR, magnetic susceptibility, molar conductance, AAS, solubility tests and
melting point/decomposition temperature. The complexes showed moderate values of
decomposition temperatures. Infrared spectral data of the Schiff base and the complexes,
indicated coordination of the Schiff bases to the metal (II) ion via azomethine nitrogen, indole
oxygen and thione sulphur. The effective magnetic moment of the complexes suggested an
octahedral geometry. The molar conductivities of the complexes were 45.8 Ω-1cm2mol-1 and
11.7Ω-1cm2mol-1 which indicated the non-electrolytic nature of the complexes. The results of
the absorbance and the empirical formula indicated that, the Schiff base is monobasic and
tridentate in nature towards the metal ions. Both the ligand and the complexes were screened
for antimicrobial activity against Staphylococcus aureus, Salmonella typhimurium,
Escherichia coli (bacteria); Aspergillus flavus, Aspergillus fumigatus and Mucor species
(fungi). Amoxicillin and Ketoconazole were used as positive control for the bacteria and fungi
isolates respectively. The results showed that the complexes are more active than the free
ligand but less active when compared with the standards.
