Parveez Gull

Design, synthesis, characterization and antimicrobial/antioxidant activities of 1, 4-dicarbonyl-phenyl-dihydrazide based macrocyclic ligand and its Cu(II), Co(II) and Ni(II) complexes.

Mononuclear transition metal complexes of Cu(II), Co(II) and Ni(II) with a newly synthesised macrocyclic ligand derived from 1, 4-dicarbonyl-phenyl-dihydrazide and 1,2-diphenylethane-1,2-dione (2:2) have been synthesised. The synthesised compounds were characterised by various physical and spectroscopic techniques including elemental analysis, FTIR, Uv-Vis., 1H NMR, mass spectra, magnetic moment and XRD. The investigation of these macrocyclic complexes established that the stability of metal-ligand coordination through N atoms as tetradentate chelates. The metal/ligands ratio of 1:1 was proposed to afford octahedral geometry for the complexes. The antimicrobial activity of the compounds against some bacterial and fungal species were done by well diffusion method and the results shows that the metal complexes have a promising biological activity comparable with the parent ligand against all bacterial and fungal species. The antioxidant activity of the compounds was also studied through scavenging effect on DPPH radicals with the copper complex showing enhanced activity than other compounds. Additionally, the docking studies predicted the high antimicrobial activity due to the interaction of ligand with the protein.

Biological Activity Studies on Metal Complexes of Macrocyclic Schiff Base Ligand: Synthesis and Spectroscopic Characterization

In this study, we prepared the macrocyclic Schiff base ligand (L) derived from 1,4-dicarbonylphenyl- dihydrazide and pentane-2,4-dione (2:2) and its CoII, CuII and NiII complexes. The compounds were characterized by the analytical and spectroscopic methods like elemental analysis, molar conductance measurements, mass spectrometry, 1H nuclear magnetic resonance (NMR), and Fourier transform infrared (FTIR) spectroscopy. The ligand behaves as a tetradentate ligand and coordinates to the metal ions via the nitrogen atoms and the complexes have the mononuclear structures. The analytical and spectroscopic results indicated that the complexes are non-electrolytes in nature and may be formulated as [M(C26H28N8O4)X2], where M = CoII, CuII and NiII and X = Cl–. The antimicrobial activities of the ligand and its complexes, as growth inhibiting agents, have been screened in vitro against different species of bacteria and fungi and the results concluded that the metal complexes are effective drugs against the tested strains as compared to the macrocyclic ligand.

Synthesis of Ni(II), Cu(II) and Co(II) complexes with new macrocyclic Schiff-base ligand containing dihydrazide moiety: Spectroscopic, structural, antimicrobial and antioxidant properties

In this study, the macrocyclic Schiff base ligand (L) derived from 1, 4-dicarbonyl-phenyl-dihydrazide and glyoxal (2:2) and its Ni (II), Cu (II) and Co(II) complexes were synthesised and were characterised by elemental analyses, FTIR, UV-Vis., mass and 1H NMR. The ligand (L) behaves as a tetradentate ligand and coordinates to the metal ions via the nitrogen atoms and the complexes have the mononuclear structures. The synthesised compounds were evaluated for their inhibition potential against bacterial and fungal strains and the assay indicated that the metal complexes exhibited a remarkable antibacterial and antifungal activity against these tested strains. In addition, the antioxidant activity of the compounds was also studied through scavenging effect on DPPH radicals with the copper complex showing enhanced antioxidant activity than other metal complexes.