Synthesis and Characterization of Potentially Bioactive Sulfamethoxazole Isatin Schiff Base and its Mn(II), Fe(II) and Ni (II) Complexes

Abstract

Sulfonamide and isatin were use for the synthesis of N-(5-Methyl-isoxazol-3-yl)-4-(2-oxo-1,2-dihydro-indol-3-ylideneamino)- benzenesulfonamide Schiff base ligand and its complexes with Mn(II), Fe(II) and Ni (II) have been synthesized and characterized by elemental analysis, conductivity measurement, magnetic measurement and spectroscopic analysis. Infrared spectra of the Schiff base revealed azomethine peak at 1639 cm-1 which shifted in the complexes to 1641 – 1687 cm-1 range, also a newpeak in the range of 717 – 786 cm-1 was observed for all the complexes. The values agree with the formation and chelation of the Schiff base through the  azomethine nitrogen and ketonic oxygen. Conductance measurement (1.64 – 30.50 Ohm-1 cm2 mol-1) suggested the non-electrolytic nature of all the complexes. Magnetic susceptibility analysis of the complexes gave results in the range of 1.94 – 5.32 B.M. suggesting octahedral geometry for all the complexes.CHN Elemental analysis was in good agreement with the proposed formulation of the complexes suggesting the ligand-metal ratio to be 2:1. Decomposition temperature (1650C – 2150C) of the complexes implied relative stability of the complexes. The Schiff base and its metal chelates were screened for antimicrobial activity against six pathogenic microbes (Staphyloccus aureus, Escherichia coli, Salmonella typhi, Aspergillus flavus, Aspergillus niger and Mucor indicus), the Schiff base shows  moderate activity, while the complexes show higher antimicrobial activity against the tested microbes.