Synthesis, characterization and antimicrobial activities of some 5-bromouracilmetal ion complexes

Abstract

Six new complexes, [Mn(Br-U)₂(H₂O)₂]×4H₂O (1), [Cd(Br-U)₂]×2H₂O (2), [Cu(Br-U)₂(H₂O)₂]×2H₂O (3), [Co(Br-U)₂(H₂O)₂]×4H₂O (4), [Ni(Br-U)₂(H₂O)₂]×4H₂O (5) and [Ag(Br-U)(Br-U-H)]×2(H₂O) (6)  were prepared by the reaction of 5-bromoouracil with MnCl₂·4H₂O, CdCl₂·2.5H₂O, CuSO₄·5H₂O, (CH₃COO)₂Co·4H₂O, (CH₃COO)₂Ni·4H₂O and AgNO₃ respectively. The complexes were characterized by melting point, elemental microanalyses, IR and ¹H NMR spectroscopy. The obtained data indicated that the ligand interacted with the metal ions in its mononegatively charged enol form in a bidentate fashion. Thermogravimetric analyses (TGA and DTG) were also carried out. The data obtained agreed well the proposed structures and showed that the complexes were finally decomposed to the corresponding metal or metal oxide. The ligand and its metal-ion complexes were tested for their antimicrobial activities against four bacterial strains (B. subtillis, S. aureus, E. coli and P. aeruginosa) by the agar-well diffusion technique using DMSO as a solvent. The obtained data showed that the complexes were more potent antimicrobial agents than the parent ligand.

KEY WORDS: 5-Bromoouracil–M²⁺ complexes, IR, Thermal analyses, ¹H NMR, Antimicrobial activity

Bull. Chem. Soc. Ethiop. 2019, 33(2), 255-268.

DOI: https://dx.doi.org/10.4314/bcse.v33i2.6