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.

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.

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.

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.

Synthesis and photoluminescence of a dendritic europium complex with carbazole moieties

A novel dendritic europium complex containing grafted carbazole units as functional peripheries was synthesized and characterized. The Foerster energy transfer from the peripheries of carbazole units to β-diketonate as well as from the hgands to the central Eu（Ⅲ） ions in the complex was demonstrated. Under the excitation of carbazole units and β-diketonate, characteristic red emission peaks at 612 nm with four shoulders due to the Eu（Ⅲ） ion transition of 5^D0→7^FJ （J=0-4） were observed for the complex.

Synthesis and Fluorescence of Novel Conjugated Europium Complex

A novel organic ligand, 6 (ortho methyl anilino carbonyl) 2 pyridine carboxylic acid (H o MAP), and the corresponding europium complex, tris(6 (ortho methyl anilino carbonyl) 2 pyridine carboxylato) europium (Eu o MAP) were designed and synthesized. The results show that solid Eu o MAP is a conjugated complex, emitting strong red fluorescence dominantly due to a ligand sensitizd luminescence mechanism. The lifetimes of 5D 0 of Eu 3+ in the complex were examined using time-resolved spectroscopic analysis, and the lifetime values were (1.50±0.01) ms for solid Eu(o MAP) 3 and (1.10±0.01) ms for 1.0×10 -5 mol·L -1 Eu(o MAP) 3 ethanol solution, respectively. Thermogravimetric analysis shows that the europium complex has good thermal stability.

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...

Hydrothermal synthesis, crystal structure and luminescence of a europium complex with phenylmalonic acid and 1, 10-phenanthroline

A new complex Eu2（PA）6（phen）2 was prepared with hydrothermal reaction using EuCl3.6H2O, phenylmalonic acid （H2phma）, and 1, 10-phenanthroline （phen）, where PA was the decarboxylated product of HEphma, phenylacetate. The crystal structure of the title complex was determined with the X-ray diffraction. The title complex was a binuclear molecule with an inversion center. Each Eu^3＋ ion was nine-coordinated with two nitrogen atoms from one phen molecule and seven oxygen atoms from five PA ligands. The carboxylic groups were bonded to the Eu^3＋ ion in three modes, the chelating bidentate, the bridging bidentate, and the bridging-chelating tridentate. The complex emits intense red fluorescence under ultraviolet light. The luminescence peaks correspond to the characteristic emission 5D0→7FJ （J=0-4） transitions of the Eu^3＋ ion.

Strongly Fluorescent LB Film of a Ternary Europium Complex

Tris (thenoyltrifluoroacetonato) mono(9-octadecylamino-4,5-diazafluorene) europium (III) was synthesized. Stable floating monolayer on pure water subphase (18 degrees C, pH 5.6) was obtained with a collapse pressure of 40 mN/m and a zero-pressure area of 0.495 nm(2) molecule(-1). The monolayers can be transferred onto hydrophilically treated substrates of quartz, calcium fluoride at a surface pressure of 25 mN/m with a transfer ratio of ca. unity. The films were characterized by UV, IR and fluorescent spectroscopy.

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.)

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

Using 2＇-Hydroxyacetophenone and as the raw material, 1-（ 2-Hydroxyphenyl ）-3-Phenyl-1, 3- Propanedione （HPPPD） was synthesized by esterification reaction and Fries rearrangement reaction. And the complexes of HPPPD with europium were also synthesized. The compounds were characterized by IR, thermo-gravimetric analysis and ^1H-NMR. The effects of phenolic hydroxyl on the luminescence properties of complexes were studied. The results show that the complexes emit strong red fluorescence and the fluorescence intensity of the ternary complex is better than that of the duality. But the complexes of HPPPD with Sm（ Ⅲ ）, Tb （ Ⅲ ）, Dy （ Ⅲ ） emit weak fluorescence. The phenomenon was interpreted by electron-effect and energy-matching mechanism. Energy transfer mechanism of the luminescence in the complex was discussed.

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

Seven ternary Eu （m） complexes were synthesized with aromatic carboxylic acid （benzoic acid, phenylacetic acid, phenylpropionic acid and cinnamic acid） as the first ligand and 1,10-phenanthro- line or 2,2＇-dipyridyl as the second ligand. The ternary Eu（ Ⅲ ） complexes were characterized by elemental analysis, IR and TG-DTG methods. In these complexes, the Eu （Ⅲ） ions are bonded to the oxygen atoms of carboxylate and the nitrogen atoms of neutral ligands. Four complexes whose second ligand is 1,10- phenanthrolin have fine thermal stability. Excitation and luminescence spectra of the tide complexes reveal that the fluorescence of the complexes in which 1,10- phenanthrolin as the second ligand are more intensive than those complexes in which 2, 2＇-dipyridyl as the second ligand. The order of the strongest emission peak of seven ternary complexes is： Eu（β-PPA）3phen 〉 Eu（BA）3phen 〉 Eu（PLA）3phen 〉 Eu（BA）3bipy 〉 Eu （ PEA）3bipy 〉 Eu （ CA ）3phen · H2O 〉 Eu （ CA ）3bipy （BA ： benzoic ; PEA ： phenylacetic ; β-PPA ：

Bright Red Luminescence from Novel Europium Complex Sensitized by Dibenzamide

A novel europium complex, bi(dibenzamide) benzoate europium(Ⅲ) (Eu-DBA-B), was synthesized. The composition and photoluminescence properties of Eu-DBA-B were investigated. The results show that the europium complex is an electroneutral complex, and it emits very strong red luminescence from (()~5D_1→()~7F_j) (j=0, 1, 2, 3, 4) transitions.

Luminescent Properties of Europium Complexes with Different Long Chains in Langmuir-Blodgett (LB) Films

A series of europium(III) complexes with different chain length, tris [2-m-pyridylmethanamido-5-phenyl- (1,3,4)-oxadiazole] mono [2-(4-n-alkylphenyl)-iminazole (4,5-f)-1,10-phenanthroline] Eu(III) [Eu(PMA)3Nn (n = 6, 10, 14,18)] were synthesized. All of these amphiphilic europium(III) complexes could form stable Langmuir film at air/water interface and could be transferred onto hydrophilic quartz and mica substrates by measurement of UV spectra in which the absorbance of the LB films at about 288 nm scales showed the linearity with the number of layers deposited. In order to investigate relation between fluorescence properties and the arrangement of molecular in LB films, surface topography of monolayer films were observed by atomic force microscopy (AFM). Results showed that the emission spectra have Eu(III) characteristic peaks and strong emission strength. It is interesting that the molecular with looser arrangement in LB films has better monochromacity, which illustrated that energy might transferred more easily from ligand to Eu(III) in loosen structure films.

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.

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.

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.

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.