Synthesis and Luminescence Study of Europium Complexes with Carboxylic Acid and 1,10-Phenanthroline Ligands

A series of euroPium(Ⅱ)eomPlexes with earboxylie aeids andl,10-Phenantl飞ro-line:Eu(L):·pllen·jHoO,wl:ereL-formate,3-hydroxy-4-metlloxybenzoate,4一metl、oxybenzoate,4一ehloroPhenoxyaeetate,and diPI、enylaeetate,were synthesizedand el、araeterized by elemental analysis,UV sPeetrum,IR speetrum and melting point.IR da亡a eonfirmed tllat euroPium 15 eoordinated wirh 0 donor atoms in earboxy!ie aeidand N donor atoms inl,10一phenanthroline.A strong ligand一loealized absorption at270 nm!ed to a series of meta!一eentered emission bands between 580 and 710 nm as-signedto ~5D_0-7F_(0.1.2.3.)

A Novel Calixarene-containing Hyperbranched Aliphatic Polyester Incorporated with Pendant Europium Complexes

1 Results Hyperbranched polymers can be easily functionalized,while the calixarene-rare earth complexes enjoy the advantages of narrow emission bands.It is expected that materials combining their advantages can possess good luminescence properties[1-2].For this reason,in this paper,a novel calixarene-containing hyperbranched aliphatic polyester incorporated with pendant europium complexes (H2O-Cal-Eu) was synthesized and characterized by FTIR,UV and element analysis.DSC measurement shows that the glass-...

Design, Synthesis, Crystal Structure and Photoluminescence Properties of Four New Europium (III) Complexes with Fluorinated β-Diketone Ligand

The strong photoluminescence properties of europium complexes with organic ligands attracted the attention of many researchers and found a wide range of uses in medical, industrial and biological fields. In this article, four new Tetrakis europium complexes 3a, 3b, 3c and 3d have been prepared using 1-phenyl-4,4,4-trifluoro-1,3-butenedionato ligand and pyridinium, bipyridinium, piperazinium and piperidinium counter cations. These complexes have been characterized by negative FAB-mass. The crystal structures of 3a, 3b, 3c and 3d were determined by single crystal X-ray diffraction analysis. The complex 3a crystallized in monoclinic form, space group P21/n with four molecules in the unit cell. The complex 3b crystallized in monoclinic form, space group P2/n with two complex molecules in the unit cell. The complex 3c crystallized in monoclinic form, space group C2/c with sixteen molecules in the unit cell. The complex 3d crystallized in monoclinic form, space group P21/n with four complex molecules in the unit cell. The complex 3a has 1,2-alternative structure, 3b has 1,3-alternative structure, 3c has cone like structure and 3d has partial cone like structure. The photoluminescence properties of these complexes have been evaluated. Strong red emissions were observed in all four complexes due to 5D0 → 7F2 transition of Europium (III) ions under UV excitation. Four β-diketone ligands acted as strong antenna ligands and transferred the absorbed energy to europium (III) ion effectively;consequently strong red luminescence was observed.

3,6-Bis-β-Dicarbonylsubstituted Carbazoles Bearing N-Spacers and Their Eu(III) Complexes as Immunofluorescent Labelling Agents

New reagents for immunofluorescence analysis of carbazole series containing fluorinated β-dicarbonyl fragments and carboxylic substituent groups separated by spacers of different lengths from the light-gathering carbazole scaffold have been developed. The markers in complex with Eu3+ ions possess stability in the aqueous phase, intense and prolonged luminescence (τ 550 - 570 μs) with characteristic emission maxima in the region of 615 nm and excitation wavelengths in the region of 380 - 390 nm, which distinguishes them from most of the analogs used. In the study of marker conjugation with streptavidin, a reagent containing 4 - 5 europium labeling complexes based on spacer-containing carbazole tetraketone was obtained. The marker-doped silicate nanoparticles exhibit intense and long-lived luminescence in the characteristic region.

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 Tb0.5 RE0.5(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.

Luminescence properties of polymers containing europium complexes with 4-tert-butylbenzoic acid

The binary europium complex EuL3 （L=4-tert-butylbenzoate） and ternary europium complexes EuL3TTAo.I （TTA=2- thenoyltrifluoroacetone）, EuL3DBMo.5 （DBM=dibenzoylmethane） and EuL3pheno.5 （phen=l, 10-phenanthroline） were synthesized. The poly（methyl methacrylate） （PMMA） or copolymer of methyl methacrylate （MMA） with acrylic acid （AA） composites doped with europium complexes were prepared by radical in-situ polymerization. The influences of the europium complexes, ligands, N,N-dimethylformamide （DMF） and monomers on the luminescence properties of the doped polymers were investigated. The results showed that the fluorescence excitation bands of binary and ternary complexes were in accordance with their ultraviolet absorption bands. All the complexes and the doped polymer composites exhibited the ligand-sensitized red characteristic emission of Eu3＋ ion. The fluorescence intensity of the polymer composites increased in the sequence of EuL3/PMMA〈EuL3pheno.5/PMMA〈EuL3DBMo.5/ PMMA〈EuL3TTAo.I/PMMA. It indicated that the introduction of a small amount of I^-diketone ligand affected the optimum excita- tion wavelength and the fluorescence intensity of polymer composites. Furthermore, DMF remarkably increased the luminescence intensity and transparence of the doped polymer composites. However, introduction of acrylic acid comonomer decreased the lumi- nescence intensity of the polymer composites.

Progresses in electroluminescence based on europium(Ⅲ) complexes

The research on electroluminescence based on europium（III） complexes has come to an important phase. This article reviewed the progresses in photoluminescence and electrohiminescence of Eu（III） complexes in recent years from the views of the design of Eu（III） complexes and optimization of device structures, and discussed some important factors influencing electroluminescence performance. The problems existing in the practical application such as the volatility and thermal stability of Eu（III） complexes in this area were discussed, and the possible corresponding solutions were briefly prospected.

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.

Thermal stability and luminescence properties of 1,10-phenanthroline-tris (m-methylbenzoate) europium (or terbium) complexes in SiO_2 gel

Silica gel luminophors containing 1, 10-phenanthroline-tris(M-Methylbenzoate) europium (or terbium) com- plexes were prepared bysol-gel method. The thermal decomposition, excitation and emissionspectra for the gel phos- phors were measured and compared with thatof solid complex powders. The thermal stability of the complexes wasen- hanced in SiO_2 host matrix and the luminescence intensityremained unchanged.

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 as 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 Photoluminescence of New Europium Complex Eu(DBM)_3(DPPZ) with Dipyridophenazine Ligand

Dipyrido [3, 2-a:2,3-c] phenazine moiety has been introduced as neutral ligand in europium complex. Therefore, a new europium complex with saturated emission, strong fluorescent intensity and good solubility was designed and synthesized for the first time. Its photoluminescence and UV properties were examined. The experimental results showed that this new Eu-complex could be used as red electroluminescent materials.

Luminescence of Eu(MBA)_2NO_3Phen Complexes

At 77 K excitation spectra,luminescence and time-resolved spectra of Eu(o-MBA)2NO3 Phen and Eu(m-MBA)2NO3 Phen (MBA:methylbenzoate,Phen 1,10-phenanthroline) complexes were measured. Spectral data show that because of steric effect of ortho-methyl substituent there occur two Eu3+ sites with slightly different chemical environment in the Eu(o-MBA)2NO3Phen complex.The local symmetnes for the central metal ions are C2v and C1,C2 or Cs,respectively.However,there is only one Eu3+ site in the Eut(m-MBA)2NO3Phen complex which is similar to the C2v Eu3+ site of the previous complex.This demonstrates that the Eu3+ ion can be used as a conformational probe in the solid state compounds.

Synthesis and Luminescence of Complexes Eu_x Y_(1-x)(phen)L_3

A series of binuclear complexes with different molar ratio of europium to yttrium with cinnamic acid and o phenanthroline were synthesized in anhydrous alcohol. Elemental analysis shows that the composition of the complexes are Eu x Y 1- x (phen)L 3 (L: C 6H 5CH=CHCOO, x =1.0, 0.7, 0.5, 0.3 and 0.1). The IR absorption spectra indicate that cinnamate is coordinated to the rare earth ions and chemical bonds are formed between rare earth ions and nitrogen atoms of o phenanthroline. Fluorescent spectra show that the emission of Eu 3+ ion can be greatly enhanced if some of europium ions in the complexes are substituted by yttrium ions.

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 spectroscopy, and fluorescence spectroscopy. The complex crystallized in triclinic crystal system, Pī space group, with a=1.17196(4) nm, b=2.36142(9) nm, c=2.59151(9) nm, α=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 nitrogen atoms from 2,2’-bpy molecule. The carboxylate groups acted as bidentate-chelating, bidentate-bridging and chelating-bridging coordination 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 emissions of the Eu(Ⅲ) ion, respectively.

Crystal Structure and Luminescence of 1,10-Phenanthroline-tris(4-methoxybenzoato)Europium

1,10 Phenanthroline tris(4 methoxybenzoate)europium, Eu( p MOBA) 3phen(where p MOBA= p methoxybenzoate and phen=1,10 phenanthroline) has been obtained in the ethanol solution. The crystal consists of binuclear molecules of the title compound. In the binuclear molecule each Eu 3+ ion is coordinated not only by four oxygen atoms from the bridging carboxylates, but also by two oxygen atoms of a bidentate carboxyl group and two nitrogen atoms of a phen chelating ligand, giving coordination number of eight. Eu O distances range from 0 2336(3) to 0 2483(3) nm. The average Eu N distance is 0 2624(4) nm. Luminescence data indicate that one Eu 3+ ion site is in low symmetry in the complex.

Synthesis and photovoltaic properties of new europium complex Eu(DBM)3(CPyBM)

A new europium（Ⅲ） complex, tris（dibertzoylmethanate）{ 1-[9-hexyl-9-carbazole]-2-（2-pyridyl）-bertzimidazole}europium（Ⅲ） [Eu（DBM）a（CPyBM）] was synthesized and used as an electron-acceptor and electron-transport layer in organic photovoltaic （PV） device. Power conversion efficiency achieved from the device was 1.04% under illumination with 365 nm UV light at 1.6 mW/cm^2. Compared with the previous reported devices based on Eu（Ⅲ） complexes, the PV performances were improved. The working mechanism of the organic PV device was discussed.

Crystal Structure and Luminescence Spectra of Ternary Europium（Ⅲ） Complex［Eu（DBM）_3（2，2＇－BIPY）］（HDBM）

The crystal structure of europium tri(dibenzoylmethanate) complex with 2.2'-bipyridyl,C70 H57 N2 O8 Eu, has been determined by X-ray diffraction. The complex crystallizes in the triclinic space group P1. The cell dimensions are a=1.3375(1) nm.b=1.8591(2) nm, c=1.1339(3) nm,α= 95.89(9) °,β=93.36(1)°,γ=85.48(1)° and Z=2. The total number of 5413 independent reflections with I>3σ(I) were used for the structure determination. The final calculated R value is 0.039. The central europium ion is octa-coordinated by six oxygen atoms and two nitrogen atoms forming a distorted square antipnsm (SAP) with the local symmetry C1. Using the Eu3+ ion as a luminescence probe. the high resolution excitation and emission spectra measured at 77 K indicate only one Eu3+ site existing in the complex. The emission spectra of 5D0→7Fj transition display the symmetry of the Eu3+ site is C1.

Synthesis, Crystal Structure and Properties of a Europium Complex with 3-Iodobenzoic Acid and 2,2'-Bipyridine

The complex [Eu（3-IBA）3·2,2＇-bipy]2 was synthesized from 3-iodobenzoic acid （3-HIBA）, 2,2＇-bipyridine （2,2‘-bipy） and EuCl3·6H2O by hydrothermal synthesis, and its crystal structure was determined by X-ray single-crystal diffraction. It is of triclinic, space group Pi, with a = 10.958（2）, b = 12.311（3）, c = 12.556（3） A, α = 81.549（3）, β = 82.404（4）, γ = 78.348（3）°, Mr = 1049.15, V= 1631.7（6） A3, Z = 1, Dc = 2.135 g/cm^3, F（000） = 980, 2（MoKa） = 0.71073 A,μ（MoKa） = 4.804 mm^-1, the final R = 0.0329 and wR = 0.0723 for 4640 observed reflections with I 〉 2σ（I）. The Eu（Ⅲ） ion is eight-coordinated and two Eu（Ⅲ） ions are held together by four 3-iodobenzoate groups in the bidentate bridging mode. The complex was characterized by DTA-TG, IR, UV and fluorescence spectra.