Synthesis, physico-chemical and antimicrobial evaluation of Co(II) and Ni(II) complexes with Schiff base derived from sulphanilamine and salicylaldehyde

Abstract

Schiff base derived from sulphanilamine and salicylaldehyde was synthesized, its reaction with nickel(II) and cobalt(II) chloride in 2:1 mole ratio yielded Ni(II) and Co(II) complexes respectively. The synthesized compounds were characterized based on melting point/decomposition temperature, solubility, molar conductance, magnetic susceptibility and infrared spectral analyses. The complexes have low molar conductance value (31.4-32.6Ω^{- 1}cm²mol^-1), indicating that they are non-electrolytes. The magnetic moment values (2.50- 3.54B.M) showed that, the metal ions in the complexes are paramagnetic in nature. Decomposition temperatures of the complexes were found to be in the range of (275 – 283ºC). Job’s method of continuous variation revealed that, the metal complexes are in 1:1 Metal- Ligand ratio. The physical and analytical data coupled with shift of spectral peaks of the Schiff base in the complexes suggested that the Schiff base act as tetradentate ligand towards metal ion and coordinated via the azomethine-N, deprotonated phenolic-O and S=O group of the sulphanilamine. The synthesized ligand and its respective metal complexes were screened for their antibacterial activity against Staphylococcus aureus (Gram-positive), Escherichia coli, (Gram-negative) bacterial strains and antifungal activity against Mucor inducus spp and Aspergillus fumigatus. The results revealed that, the Schiff base and the metal complexes showed significant antibacterial and antifungal strength at high concentrations

Keyword: Synthesis, characterization sulphanilamine, salicylaldehyde, Schiff base