Luminescent lanthanide mixed N-phthaloylglycinate and terephthalate coordination polymers: Structural and optical properties.

A new class of lanthanide mixed-carboxylate ligands compounds with formula {[Ln (phthgly) (bdc)(H O) ]·(H O) } , labelled as Ln : Eu (1) and Gd (2) coordination polymers (CP) were synthesized under mild reaction conditions between lanthanide nitrate salts and a solution of N-phthaloylglycine (phthgly) and terephthalic (bdc) ligands. The (1) and (2) coordination polymers were formed by symmetric binuclear units, in which phthgly and bdc carboxylate ligands are coordinated to the lanthanide ions by different coordination modes. Surprisingly, all organic ligands participate in hydrogen bonding interactions, forming an extremally rigid crystalline structure.

Enhancing the Luminescence of Eu(III) Complexes with the Ruthenocene Organometallic Unit as Ancillary Ligand.

Five novel Eu(III)-β-diketonate complexes containing ruthenocene ancillary ligands (1,1'-bis(diphenylphosphoryl)ruthenocene─RcBPO) were synthesized and characterized. The coordination compounds presented the general formula [Eu(β-dik)(RcBPO)], where β-dik stands for 2-thenoyltrifluoroacetonate (tta), 3-benzoyl-1,1,1-trifluoroacetone (btf), 2-dibenzoylmethanate (dbm), 2-acetyl-1,3-indandionate (aind), and 2-benzoyl-1,3-indandionate (bind), and RcBPO stands for 1,1'-bis(diphenylphosphoryl)ruthenocene. The [Eu(aind)(RcBPO)] complex crystallizes in a monoclinic Cc non-centrosymmetric space group with the europium site environment, assuming a bicapped trigonal prism coordination polyhedron with the symmetry point group close to .

Luminescent and magnetic materials with a high content of Eu(3+)-EDTA complexes.

Bifunctional optical magnetic materials with a high europium content have been prepared. Chelating groups were introduced on the Fe3O4 surface with organosilanes containing ethylenediaminetetraacetic acid (EDTA) derivatives, which were previously prepared via a reaction between EDTA-dianhydride and aminoalkoxysilane agents: 3-(trimethoxysilyl)propylamine (1N), N-[3(trimethoxysilyl)propyl]ethylenediamine (2N) and N(1)-(3-trimethoxysilylpropyl)diethylenetriamine) (3N). The first coordination sphere of Ln-EDTA complexes present on the modified surfaces of Fe3O4 particles was completed by addition of β-diketonate ligands (tta: thenoyltrifluoroacetone, dbm: dibenzoylmethane, bzac: benzoylacetone and acac: acetylacetone) in order to improve their luminescence properties.

Red-green emitting and superparamagnetic nanomarkers containing Fe3O4 functionalized with calixarene and rare earth complexes.

The design of bifunctional magnetic luminescent nanomaterials containing Fe3O4 functionalized with rare earth ion complexes of calixarene and β-diketonate ligands is reported. Their preparation is accessible through a facile one-pot method. These novel Fe3O4@calix-Eu(TTA) (TTA = thenoyltrifluoroacetonate) and Fe3O4@calix-Tb(ACAC) (ACAC = acetylacetonate) magnetic luminescent nanomaterials show interesting superparamagnetic and photonic properties.

Photoluminescence of europium(III) dithiocarbamate complexes: electronic structure, charge transfer and energy transfer.

For the first time, we observed photoluminescence in Eu(III) dithiocarbamate complexes at room temperature -- more specifically in [Eu(Et(2)NCS(2))(3)phen], [Eu(Et(2)NCS(2))(3)bpy] and the novel [Eu(Ph(2)NCS(2))(3)phen], where phen stands for 1,10-phenanthroline and bpy for 2,2'-bipyridine. Correlations between the electronic structure of the dithiocarbamate ligands on one hand, and covalency, intensity, and ligand field spectroscopic parameters on the other, could be established. Moreover, the relative values of the emission quantum efficiencies obtained for these complexes, as well as their dependence with temperature, could be satisfactorily described by a theoretical methodology recently developed.

Synthesis and spectroscopic behavior of highly luminescent Eu(3+)-dibenzoylmethanate (DBM) complexes with sulfoxide ligands.

In this paper the synthesis, characterization and photoluminescent behavior of the [RE(DBM)3L2] complexes (RE=Gd and Eu) with a variety of sulfoxide ligands; L=benzyl sulfoxide (DBSO), methyl sulfoxide (DMSO), phenyl sulfoxide (DPSO) and p-tolyl sulfoxide (PTSO) have been investigated in solid state. The emission spectra of the Eu(3+)-beta-diketonate complexes show characteristics narrow bands arising from the 5D0-->7F(J) (J=0-4) transitions, which are split according to the selection rule for C(n), C(nv) or C(s) site symmetries. The experimental Judd-Ofelt intensity parameters (Omega2 and Omega4), radiative (A(rad)) and non-radiative (A(nrad)) decay rates, and R02 for the europium complexes have been determined and compared.

Steady-state luminescence investigation of the binding of Eu(III) and Tb(III) ions with synthetic peptides derived from plant thionins.

This work reports Eu(III) and Tb(III) luminescence titrations in which the lanthanide ions were used as spectroscopic probes for Ca(II) ions to determine the metal binding ability of Ac-NESVKEEGGW-NH(2) and Ac-NESVKEDGGW-NH(2). These decapeptides correspond to the putative calcium binding region of the plant antifungal proteins SI-alpha1 from Sorghum bicolor and of Zeathionin from Zea mays, respectively. The luminescence spectra for the Eu(III)-decapeptide system (red emission) with the excitation at the Trp band at 280 nm showed an enhancement of the intensities of the 5D(0)-->7F(J) transitions (where J=0-4) with increments of Eu(III) ion concentration.

Synthesis and photophysical study of highly luminescent coordination compounds of rare earth ions with thenoyltrifluoroacetonate and AZT.

This work presents the study of the interaction between zidovudine (AZT) and rare earth (RE) ions with thenoyltrifluoroacetonate (TTA). The complexes [RE(TTA)(3) x (AZT)(2)] (where RE(III)=Eu and Gd) were prepared by reaction between the [RE(TTA)(3) x (H(2)O)(2)] precursors and AZT dissolved in acetone in the molar ratio 1:2. The obtained luminescent materials were characterized by microanalyses (C, H, N), complexometric titration, IR spectroscopy, X-ray powder diffraction and thermal analysis (DSC and TG/DTG).