Browsing by Author "Sisay, Girma"

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    Synthesis and Characterization of some Transition Metal Complexes With O,N,O and O,O Donor Ligands
    (Addis Ababa Universty, 2011-06) Sisay, Girma; Shyamala, B.S. (PhD)
    Novel Schiff base mixed ligand complexes of Cu(II) and Zn(II) were prepared from 3-AC and 4-AR by template synthesis. Also, new metal complexes of chromium(III), iron(III) and copper(II) ions were synthesized with 4-AR. All the complexes were characterized by elemental and metal ion analyses, IR and UV-Vis spectroscopy, magnetic susceptibility data and conductance measurements. Analytical data of the mixed ligand complexes shows a M:L ratio of 1:2 and 1:1 for copper and zinc complexes, respectively. Based on these data, an octahedral geometry for Cu(II) complex and a tetrahedral geometry for the Zn(II) complex was proposed. In the Cu(II) complex, the mixed ligand acts as an O,N donor and in the Zn(II) complex, it acts as an O,N,O donor. Attempt to synthesize the mixed ligand complexes with Cr(III), Fe(III) and Ni(II) ions were not successful. Complexation of chromium(III), iron(III) and copper(II) ions were carried out with 4-AR successfully. The ligand coordinates through the phenolic oxygen and the carbonyl oxygen atoms (i.e. the ligand behaves as O,O donor). An octahedral geometry for Cr(III) and Fe(III) complexes and a tetrahedral geometry for the Cu(II) complex was proposed. Attempt to synthesize the Ni(II) and Zn(II) complexes with 4-AR were not successful. . Key words: Mixed ligand complexes, 3-aminocoumarin (3-AC), 4-acetylresorcinol (4-AR), Schiff base