Synthesis, Characterization and Antibacterial Study of Co (II) and Cu (II) Complexes of Sulfamethoxazole

Complexes of Co and Cu with SMZ were successfully synthesized (1:2 molar ratio) in good yield and characterized by using UV-vis, FTIR, melting point/decomposition temperature, electrical conductivity and solubility in different solvents of varying polarity and proticity. All the prepared complexes were coloured. From the IR results, 529, 631, 528 and 779 cm-1 bands were observed in the spectra of the complexes which were absent in the free ligand spectrum thus, showing the presence of metal-ligand bond (coordination) in the complexes. The electronic spectral data of the complexes suggest an octahedral and tetrahedral geometry for all the complexes. The ligand and the Co (II) complex were found to be soluble polar protic solvents at both room and elevated temperature while, Cu (II) complex was found to be insoluble in polar protic solvent (ethanol) at room temperature but soluble at elevated temperature. The metal complexes are insoluble in non-polar solvent at both temperatures. More so, the ligand was found to be soluble in non-polar solvent at both temperatures. The electrical conductivity measurements indicated that the synthesized complexes are non-electrolytes. The synthesized metal complexes showed improved broad-spectrum antimicrobial activity against E. coli and S. aureus as compared to the ligand. Thus, the complexes [Co(C10H11N3O3S)] and [Cu(C10H11N3O3S)] are good leads to be developed into antibiotics against the tested antimicrobial agents (E. coli and S. aureus).