Synthesis, structural elucidation and antimicrobial activities of 5-(3-nitrophenyllazo)-6-aminouracil and its complexes with some transition metal ions

In this study, 5-(3-nitrophenyllazo)-6-aminouracil was prepared by linking 3-nitro aniline to 6-aminouracil. The (1:1) complexes of this ligand with Fe⁺3, Co⁺², Ni⁺², Cu⁺² and Zn⁺² were prepared and characterized by elemental analysis for C, H and N, thermal analyses (TGA and DTA), FT-IR, ¹H NMR. The molecular weight of the ligand was determined by mass spectral measurement and its fragmentation pattern was reported. The metal content of the complexes was determined by EDTA complexometric titrations and the coordination number of metal in complexes was confirmed by magnetic susceptibility measurements. Antimicrobial activities for ligand and its complexes were studied. The IR and ¹H NMR studies confirmed that 5-(3-nitrophenyllazo)-6-minouracil behaves as monobasic bi dentate ligand bonding to the metal ion through both NH₂ group and N=N groups forming six membered ring and The magnetic moments measurements indicated octahedral geometry for Fe⁺³ complex, tetrahedron structure for Co⁺², Ni⁺², Cu⁺² complexes and square planar geometry for Zn⁺² complex. Antimicrobial activity measurements indicated that Co⁺² and Ni⁺² complexes are biologically active towards bacteria gram (-ve), gram (+ ve) and fungi, while Zn⁺² complex showed high resistance towards gram (+ ve) bacteria and medium resistance towards gram (-ve).