Fe(III), Ni(II), Cu(II) and UO_2(VI) complexes with new schiff base ligands derived from 3-formyl-4-hydroxy-1,8- naphthyridin-2-one with o- and p-phenylenediamine

摘要

New Schiff base ligands have beenfrom the condensation of 3-formyl-4-hydroxy-1,8-naphthyridin-2-one with 0-and p-phenylenediamine,H_2L~1 and H_2L~2, respectively. Fe(III), Ni(II),Cu(II) and UO_2(VI) complexes were prepared andcharacterized by chemical analyses, IR, electronic andmass spectra as well as thermal analyses and magneticmeasurements. The Schiff base ligands behave asmono- or dibasic tetradentate ligands towards the metalcations. Different Ni(II) complexes are obtained insimilar reactions of the ligands H_2L~1 and H_2L~2with Ni(Oac)_2.4H_2O having the formulae [L~1Ni_2(Oac)_2] and [L~2 Ni(OH_2)_2]_2, respectively.The coordination geometries around the Ni(II) cationsare square-planar for the H_2L~1 complex andoctahedral for the H_2L~2 complex . The UO_2(VI)cation yields a mononuclear complex with N_2O_2coordinating sites with the ligand H_2L~1. Thecomplexes of Fe(III) and Cu(II) give the same productsfor both ligands, a monemer with ligand H_2L~1 and adimer with ligand H_2L~2. Magnetic moments andelectronic spectral data indicate that the geometries ofthe Fe(III) and Cu(II) complexes are octahedral and theUO_2(VI) complex is pentagonal-bipyramidal.