Synthesis and Photoluminescence of Three Europium （ Ⅲ ） Ternary Complexes with New Secondary Ligands of Different Structure

Three new 1,10-phenanthroline derivatives, dipyrido (3,2-f: 2,3-h) quinoxaline (DPQN), imidazo (5,6-f)-( 1,10)-phenanthroline (IP) and 3-phenyl-imidazo (5,6-f)- ( 1,10)-phenanthroline (PIP) were designed and synthesized was a secondary ligand to coordinate with europium (Ⅲ) ion while dibenzoylmethane (DBM) was used as the first ligand. The compositions of the ligands and the europium (Ⅲ) ternary complexes were confirmed by elementary analysis, IR and ^1H-NMR-spectroscopy. The UV-visible absorption spectra, thermal stability, photoluminescence spectra, quantum yield and fluorescence life time of the Eu( Ⅲ) complexes were investigated. The effect of the structure of the secondary ligand on the photoluminescence of the complexes was discussed. The results show that the synthesized Eu(Ⅲ) complexes are good red-emitiing materials for potential application in fabrication of organic electroluminescence devices.     

Synthesis and Characterization of Eu（ Ⅲ ） Quaternary Complex with 2,2-Dihydroxymethyl Propionic Acid

A new quaternary complex with 2, 2-dihydroxymethyl propionic acid and 1, 10-phenanthroline, Eu(CH3C (CH2OH)2CO0) (NO3)2 (phen), was synthesized in ethanolelemental analysis, IR and solid-state ^13C NMR. The result of molar electro conductivity of complex indicates that it is non-electrolyte. Solution properties and UV spectra of complex further verify that the complex is different from that of ligants. In addition, the analytical results also imply that the two hydroxyl groups of 2,2-dihydroxvmethvl propionic acid are not involved in the coordinate reaction.     

Synthesis and Properties of Ternary Europium Complexes with Aromatic Carboxylic Acid and ,Nitrogen-Containing Heterocyclic Ligand

Synthesis and Properties of Ternary Europium Complexes with Aromatic Carboxylic Acid and Nitrogen-Containing Heterocyclic Ligand     

Structure of Complexes of Lanthanides with N, N＇-Dimethyl-3-Oxa-Glutaramic Acid

A new stripping agent N, N-dimetbyl-3-oxa-glutaramic Acid (DOGA) was used in TRPO process to simplify the TRPO process. The structures of the complexes of the DOGA with Eu(Ⅲ), Nd(Ⅲ), La(Ⅲ) were characterized with extended X-ray absorption fine structure spectroscopy (EXAFS), infrared spectra (IR) and mass spectra (MS). The molecular formula of the complexes of Eu( Ⅲ ) and Nd( Ⅲ ) is deduced to be M(DOGA)3, and only La( Ⅲ ) can form the complex HM(DOGA)4 under condition of high consistency of the DOGA. The coordination number of Ln( Ⅲ ) in the complexes is 8, and all of coordinated donor atoms are O atoms. For Eu( Ⅲ ), Nd( Ⅲ ), the coordination numbers of O atom in the first coordination shell is 6 and the average coordination bond lengths of Ln - O are 0.240 nm, 0.244 nm respectively,while the numbers of the second O shell are 2.4, and the average coordination bond lengths of Ln - O are 0.260 nm,0. 262 nm. For La( Ⅲ ), the coordination numbers of O atom in the first coordination shell is 6 and the average coordination bond lengths of La - O are 0.258nm, while the number of O atom in the second coordination shell is 4.4, and the average coordination bond length of La - O is 0.28 nm. The results of IR and MS show that there is no water coordinating with Ln( Ⅲ ) in the complexes.     

Synthesis and Characterization of Mesoporous Europium （Ⅲ） Silicate Molecular Sieves

The discovery of MCM-41 in 1992[1]opens up anewera for mesoporous molecular sieve science .Thatmesoporous molecular sieve possessing very large spe-cific surface area has great potential application in in-dustrial catalysis and environmental processes .Av…     

Synthesis of Eu （Ⅲ） and Tb （Ⅲ） Complexes with New Aryl Amide Type Tetrapodal Ligand and Their Luminescence Properties

A new aryl amide type tetrapodal ligand L (1,1,1,1-tetrakis-{[(2-benzylaminoformyl) phenoxyl] methyl} methane) and its europium and terbium nitrate complexes were synthesized. The luminescence properties of these complexes were also studied.     

Synthesis, Structure and Photoluminescent Properties of A Novel Oxadiazole-Functionalized Europium（ Ⅲ ） Complex

Scheme1Synthesisrouteof2benzamide5phenyl[1,3,4]oxadiazole(HL1)andgaveabuffersolution.After2h,thesolutionwas pouredintowater;andthewhiteprecipitatewascol lectedanddriedundervacuum.PureproductHL1was obtainedbyre crystallizationfromethanol,m.p.211～213℃.Ana…     

Sol-Gel Synthesis and Luminescent Characteristic of Doped Eu^3 ＋ Silicate-Silica Phosphor

Silicagelphosphorsdopedrareearthionshave attractedgreatattentionofmanyresearchersdueto theseadvantages,suchashighersamplehomogeneity,purityandstable,efficientandenvironmentallyfriend lyphotoluminescencematrixmaterials,whichisless toxicleadtonetconversione…     

Investigations on Valence-Change Behaviors of Europium Ions in Eu-Doped Aluminate and Silicate Phosphors

Compounds of Sr3Al2O6∶Eu, Sr4Al14O25∶Eu, and BaZnSiO4∶Eu were synthesized by high-temperature solid state reactions. The doping Eu3 ions were partially reduced to Eu2 in Sr4Al14O25∶Eu and BaZnSiO4∶Eu prepared in an oxidizing atmosphere, N2 O2. However, such an abnormal reduction process could not be performed in Sr3Al2O6∶Eu, which was also prepared in an atmosphere of N2 O2. Moreover, even though Sr3Al2O6∶Eu was synthesized in a reducing condition CO, only part of the Eu3 ions was reduced to Eu2 . The existence of trivalent and divalent europium ions was confirmed by photoluminescent spectra. The different valence-change behaviors of europium ions in the hosts were attributed to the difference in host crystal structures. The higher the crystal structure stiffness, the easier the reduction process from Eu3 to Eu2 .     

Synthesis of 1-（2-Hydroxyphenyl）-3-Phenyl-1,3-Propanedione and Luminescence Properties of Its Europium Complexes

Synthesis of 1-(2-Hydroxyphenyl)-3-Phenyl-1,3-Propanedione and Luminescence Properties of Its Europium Complexes     

Synthesis and Fluorescence Properties of Europium,Terbium Doped Zn^2＋, Cd^2＋, and Cr^3＋ Complexes

Europium and terbium complexes with strong fluorescence intensity and long fluorescence lifetime were prepared. By replacing half of the europium or terbium ion with M （M = Zn^2＋, Cd^2＋, and Cr^3＋） using the doped method, and then incorporating it with 18-crown-6 ether and terephthalic acid, six heteronuclear samples EuZnLL＇Cl3·3H2O（1）, EuCdLL2＇Cl3·5H2O（2）, EuCrLL＇Cl4· 4H2O（3）, TbZnLL＇Cl3·4H2O（4）, TbCdLL＇2Cl3·4H2O（5）, and TbCrLL＇2Cl4 ·4H2O（6） （L = terephthalic acid, L＇= 18-Crown-6 ether） were obtained. The elemental analysis, molar conductivities, rare earth complexometry, Fourier Transform Infrared Spectroscopy （FT-IR）, ultraviolet （UV）, TGA, fluorescence intensity, and fluorescence lifetime of the samples were measured. The results showed that there were good luminescence properties for heteronuclear complexes （1）, （2）, （4）, and （5）, which were even stronger than those of the homonuclear complexes Eu2LL＇2Cl4·4H2O and Tb2LL＇2Cl4 ·4H2O, but the luminescence properties of EuCrLL＇Cl4·4H2O, TbCrLL＇Cl4·4H2O were very weak. A possible luminescence mechanism was suggested by the organic-inorganic doped mechanism and the law of intramolecular energy transfer.     

Synthesis,crystal structure,and fluorescence of two dimeric europium（Ⅲ） complexes with 2-（trifluoromethyl）benzoate

Two complexes [Eu2（2-TFMBA）6（2,2′-bipy）2]·2H2O （1） and Eu2（2-TFMBA）6（1,10-phen）2 （2） （2-TFMBA=2-（Trifluoromethyl） benzoate; 2,2′-bipy=2,2′-bipyridine; 1,10-phen= 1,10-phenanthroline） were synthesized by solvent method and determined by X-ray diffraction analysis. Complex 1 crystallizes in monoclinic system with space group P21/c, whereas complex 2 crystallizes in triclinic system with space group Pi. Both are binuclear molecules with an inversion center. In complex 1, two center Eu^3＋ ions are linked together by four 2-TFMBA ligands in bidentate-bridging mode. Each Eu^3＋ ion is eight-coordinated with six O atoms from five 2-TFMBA ligands and two N atoms from one 2,2′-bipy molecule. In complex 2, two center Eu^3＋ ions are linked together by four 2-TFMBA ligands in two modes, namely, bidentate-bridging and tridentate-bridging. Each Eu^3＋ ion is nine-coordinated with seven O atoms from five 2-TFMBA ligands and two N atoms from one 1,10-phen molecule. The two complexes both exhibited strong red fluorescence under ultraviolet light, and the ^5D0→^7Fj （j=0-4） transition emissions of Eu^3＋ ion were observed in their emission spectra.     

Synthesis, Characterization and Fluorescence Properties of Europium, Terbium Complexes with Biphenyl-4-Carboxylic Acid and o-Phenanthroline

Two series of solid complexes of europium and terbium with biphenyl 4-carboxylic acid and phen were synthesized and characterized in this report. Their elemental analysis, molar conductivities and TG-DTA studies indicate that the complexes have the composition of Eu(phen)L3·1/2H2O, Eu0.5RE0.5(phen)L3·1/2H2O; Tb(phen)L3·H2O and Tb0.5RE0.5(Phen)L3·1/2H2O. (RE=Y3 , La3 and Gd3 ; L=biphenyl 4-carboxylic acid; phen=o-Phenanthroline). The studies of their IR, UV 1H NMR and molar conductivities demonstrate that biphenyl 4-carboylic acid is bounded with RE(Ⅲ) ion. Rare earth ions coordinate with two nitrogen atoms of phen molecules directly in these rare earth complexes. The fluorescence spectra and fluorescence lifetimes of the rare earth complexes show that the fluorescent intensity and lifetime of a series of europium complexes are longer than those of the series of terbium complexes as having the some ligands. There are better fluorescent intensity and lifetime of hetero-nuclear rare earth complexes than homo-nuclear rare earth complexes for europium complexes. The fluorescence emission intensity of Eu3 is raised by inert fluorescent rare earth ions (Y3 , Gd3 and La3 ), but in Tb3 hetero-nuclear rare earth complexes the intensity of Tb3 ions are quenched by the inert fluorescent rare earth ions.     

Synthesis,crystal structure and fluorescence property of 1-D europium complex with 2,3-difluorobenzoate

A new chain europium complex [Eu(2,3-DFBA)3·(H2O)2]n(2,3-DFBA=2,3-difluorobenzoate) was synthesized by solvent method.X-ray single-crystal diffraction analysis revealed that Eu3+ ions were linked through 2,3-DFBA groups via alternate bidentate-bridging and tridentate chelating-bridging coordination modes to form a one-dimensional(1-D) polymeric chain.Each Eu3+ ion is eight-coordinated by six O atoms of five 2,3-DFBA ligands and two water molecules.The abundant hydrogen bonds between chains resulted in a two...     

Synthesis, crystal structure and fluorescence of a new europium complex with 2-bromobenzoate and 2,2′-bipyridine

A new complex of {[Eu2(2-BrBA)6(2,2'-bpy)2]2.CH3CH2OH·H2O} (2-BrBA=2-bromobenzoate; 2,2'-bpy=2,2'-bipyridine) was prepared by solvent method and characterized with X-ray single-crystal diffraction, IR spectroscopy, UV spectrscopy, and fluorescence spectroscopy. The complex crystallized in triclinic crystal system, PT space group, with a=1.17196(4) nm, b=-2.36142(9) nm, c=2.59151(9) nm, a=113.266(2)°, β=101.100(2)°, and γ=94.400(2)°. Two independent dinuclear molecules were contained in the asymmetric unit. The two molecules were similar to each other. Each Eu(Ⅲ) ion was nine-coordinated with seven oxygen atoms from five 2-BrBA ligands and two ni-trogen atoms from 2,2'-bpy molecule. The carboxylate groups acted as bidentate-chelating, bidentate-bridging and chelating-bridging coor-dination modes. The complex adopted a distorted monocapped square-antiprism coordination geometry. Five peaks at 579, 591, 613, 652,and 697 nm appeared in the fluorescence spectrum, corresponding to 5D0→7F0, 5D0→7F1, 5D0→7F2, 5D0→7F3, and 5D0→7F4 transition emis-sions of the Eu(Ⅲ) ion, respectively.