Syntheses, Characterization, Structure And Properties Of Complexes With Bis (Beta-diketonate) Ligands

In this paper, the study for lanthanide luminescent complexes and polynuclear complexes with bis(beta-ketonate) ligands has been reviewed. Six bis(beta-ketonate) ligands, seven lanthanide ternary complexes and six transition metal complexes with bis(beta-ketonate) ligands were synthesized.This thesis consists of the following two parts:Part 1: Three bis(beta-ketonate) ligands: l,4-bis(3-phenyl-l,3-propanedion) benzene (H2L1), 1,3-bis(3-phenyl-1,3-propanedion) benzene (H2L2) and 4,4' -bis (3-phenyl-l,3-propanedion) biphenyl (H2L3) were prepared. Ligands (H2L1 and H2L2) were characterized by UV, IR, 1H NMR and X-ray single-crystal diffraction. Crystal structure analysis shows that the ligands adopt a planar structure as expected to maximize conjugation with the two diketonate units arranged asymmetrically about the 1, 3-phenylene spacer and one diketonate is oriented in the opposite direction from the other. The room-temperature emission spectrum of H2L1 exhibits an emission band at 437nm. Seven lanthanide ternary complexes [Eu(Ⅲ), Sm(Ⅲ), Tb(Ⅲ), Nd(Ⅲ), Gd(Ⅲ), Dy(Ⅲ), Er(Ⅲ)] with H2L2 and phenanthroline were also synthesized. Through investigating the sensitizing properties of H2L2 by luminescence spectroscopy of these complexes it can be concluded that the ligand 3ππ * state is well placed to allow energy transfer to Eu(Ⅲ) and Sm(Ⅲ) excited states, following UV absorption.Part 2: Three 4-acetyl-bis-pyrazolone ligands were synthesized: 1,4-bis(3-methyl-1-phenyl-5-pyrazolone-4-yl) benzenedione (H2L4), 1,4-bis(3-methyl-1-phenyl-5-pyrazolone-4-yl) benzenedione (H2L5), 2,6-bis(3-methyl-l-phenyl-5-pyrazolone-4-yl) pyridindione (H2L6). The H2L5 ligand was characterized by elemental analysis, UV, IR, 1H NMR, 13C NMR, MS and COSY spectra. The preparation, crystalstructures of copper(Ⅱ), manganese(Ⅱ) , iron(Ⅲ) dinuclear complexes with H2L5, [Cu2L52(DMSO)2] (1), [Mn2L52(DMF)3H2O] (2), [Mn2L52(Phen)2] (Phen is 1,10-phenanthroline) (3) , [Fe2L53] (4) and copper(Ⅱ), nickle(Ⅱ) complexes with H2L6, CuL6(py) (py is pyridine) (5), [Ni2L62 (DMF) 2(H2O) 2] (6) are also presented respectively. Their crystal structure shows that the molecular structure of 1 consists of a centrosymmetric dimer containing two Cu(Ⅱ) ions bridged and chelated by two through their β-diketone moieties, the molecules of 2 and 3 feature a dinuclear array of Mn2+ ions chelated and bridged by two (L5)2- iigands wrapped around the molecular axis in a helical manner, complex 4 exhibits an irregular triple-stranded helicate.