Synthesis Of Some Mixed Ligand Complexes Derived From Catechol And 2- Aminopyridine And Their Biological Activity

The complexing ability of catechol (L1) and 2-aminopyridine (L2) with Mn(II), Fe(III), Co(II), Ni(II) and Cu(II) ions have been investigated by different techniques, in terms; elemental analyses (C,H and N), electron paramagnetic resonance spectra, infrared, electronic spectra, magnetic moments, mass spectra, molar conductance measurements and thermogravimetric analysis. The elemental analysis data reveal the formation of 1:1:1 [M:Ll:L2] complexes. The electron paramagnetic resonance spectra of all complexes under investigation show the existence of paramagnetic phenomena for Mn(II), Fe(III) and C (II) complexes and support the geometrical structures of these complexes. The infrared spectral data were agreed with the coordination sites of the free ligand with the central metal ion through -OH, HC=N and NH2 groups. The electronic absorption spectral data display the electronic transitions of the ligand and suggest an octahedral structure for all synthesized complexes except Ni(II) complex which has a square planar structure. The magnetic moments exhibit a paramagnetic phenomena for some complexes, and a diamagnetic phenomena for Co(III) and Ni(II) complexes. The mass spectrum of Fe (III) complex shows the fragmentation process m/e+ for this complex. The molar conductance measurements show the presence of non-electrolyte nature. The thermogravimetric analysis data of Mn(II), Co(II) and Ni(II) complexes display the existence of hydrated and coordinated water molecules. The antibacterial activities of the metal ions, ligands, and mixed ligand complexes under investigation have also been studied on some types of pathogenic bacteria