Synthesis, Characterization and Antimicrobial Screening of Ni(II), Cu(II) and Co(II) Complexes of Some Schiff Base Ligands Derived from 5-Aminouracil

The synthesis, spectroscopic and biological activity studies of Ni(II), Cu(II) and Co(II) complexes of Schiff base ligands derived from 5-aminouracil, 2-hydroxy-1-naphtaldehyde, 2,4-dihydroxybenzaldehyde and salicylaldehyde are reported. In all cases, the complexes appear to be monomeric. The ligands coordinate in bidentate fashion to Ni(II) and Co(II) but in a tridentate fashion to Cu(II) by coordinating to the carbonyl oxygen atom in the 4th position of uracil ring. The biological activities of the Schiff bases and metal complexes have been tested in vitro against a number of bacteria and a fungus. Ni(II) complexes derived from the saliciylaldehyde Schiff base ligand showed good antimicrobial activity whereas a Co(II) complex derived from the same ligand showed good anticandidal activity. Key Words: 5-aminouracil, Schiff base, biological activity.