Synthesis, characterization and antimicrobial studies of Co(II), Ni(II), Cu(II) and Zn(II) complexes of a Schiff base derived from 3-nitrobenzaldehyde with Arginine

Abstract

The Schiff base was synthesized by condensation of 3-nitrobenzaldehyde and Arginine and its metal (II) complexes were prepared from the divalent chloride salts of Cobalt, Nickel, Copper and Zinc. The Schiff base and its complexes were characterized on the basis of solubility, melting/decomposition temperature, molar conductance, magnetic susceptibility, Job analysis, FT-IR and elemental analysis. The complexes were non-electrolytes in dimethyl sulphoxide and the FT-IR spectra of the Schiff base showed band at 1622 cm-1 assignable to ʋ(C=N). The band shifted to the lower frequencies in the spectra of the complexes at the ranges; 1607 - 1618cm-1 and this also suggests coordination through azomithine nitrogen and carboxylate oxygen. The free Schiff base and its complexes have been tested in vitro for their antibacterial as well as antifungal activity. The results revealed the compounds were found to be active against some selected bacterial and fungal isolates with an enhanced activity in the complexes.