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.

Sol Gel Assembly and Luminescence of SiO_2/PEMA Hybrid Material Incorporated with Terbium Complex

Ethyl methacrylate (EMA) doped with luminescent ternary terbium complex (Tb(acac) 3·dam) with acetylacetone (Hacac) and diantipylmethane (dam) was incorporated into the microporous silica gel. With the polymerization of EMA, the hybrid material containing Tb(acac) 3·dam was obtained. The hybrid material exhibited good toughness and transparency and higher thermal stability than that of the pure complex and pure polymer matrix. In the range of doping concentration of Tb(acac) 3·dam (0.05%, 0.1%, 0.2%, 0.5%, 1.0%, 2.0% and 5.0%), emission intensity increases with the increasing of corresponding doping concentration and concentration quenching effect has not taken place.

Organic Light Emitting Devices Based on Terbium Complex

Rare earth complex TbY(m-MOBA)_6(phen)_2·2H_2O was synthesized, which was first used as an emitting material in electroluminescence. The properties of monolayer device with the rate of 1000 r·min^(-1) (70 nm) and the impure concentration of 1∶5 were the best. And the highest brightness of this device reached 21.8 cd·cm^(-2) at a fixed bias of 20 V. Bright green emission can be obtained from the optimized double-layer device, and the highest EL brightness of the device reached 289 cd·m^(-2) at the voltage of 21 V.

Organic Light-Emitting Devices Based on Terbium Complex

Rare earth complex with a structure of [Tb(m-MBA)_3phen]_2·2H_2O was synthesized,which was used as light-emitting material in electroluminescence. The terbium complex was dispersed in poly (N-vinylcarbazole) (PVK) as an emitting layer which is made by spin coating. Two kinds of devices were fabricated with structures: as following device Ⅰ: glass/ITO/PVK: terbium complex/PBD/LiF/Al, and device Ⅱ: glass/ITO/PVK: terbium complex/AlQ/LiF/Al. The photoluminescent (PL) and electroluminescent (EL) behaviors of the devices were investigated. Bright green emission can be obtained from optimized device Ⅱ,and the highest EL brightness of it reaches 140 cd·m (-2) at the voltage of 20 V.

Organic Light-Emitting Device Based on Terbium Complex

A new rare earth complex Tb(p-MBA)_3phen was synthesized, which is first used as an emitting material in organic electroluminescence. By doping it into the conjugated polymer PVK, single-layer and double-layer devices were fabricated with structures: device 1: ITO/PVK∶Tb(p-MBA)_3phen/Al; device 2∶ ITO/PVK: Tb(p-MBA)_3phen/AlQ/LiF/Al. The characteristics of these devices have been investigated. The emission of PVK is completely restrained, and only the pure green emission from Tb^(3+) can be observed in electroluminescence. The optimized device 2 has better monochromatic characteristics with the maximal brightness of 152 cd·m^(-2) at the voltage of 20 V.

Luminescent Thin Film of Doped Terbium Complex Obtained by Sol-Gel Method

The transparent luminescent thin films of doped terbium complex were obtained by sol gel method. The result indicates that rare earth carboxylates with poor solubility can be homogeneously doped into sol matrix in situ. The fluorescence spectra show that the thin film material emits the characteristic narrow band emission of Tb 3+ under the UV excitation.

Luminescence of Terbium Complexes Incorporated into Silica Matrix

Binary and ternary terbium complexes were synthesized: Tb(N PA) 3·4H 2O and Tb(N PA) 3(phen·2H 2O (N HPA = N phenyl 2 aminobenzoic acid and phen = 1,10 phenanthroline). These complexes were introduced into inorganic polymeric porous silica matrix by the sol gel method. The luminescence behavior of the complexes in silica gels was compared with the corresponding solid state complexes by means of emission, excitation spectra and luminescence lifetimes. The result indicates that the terbium ions show fewer emission lines and lower emission intensities in the silica gel than those in pure terbium complexes. The lifetimes of terbium ions in silica gel doped with terbium complexes become longer than those of terbium complexes.

Organic Light Emitting Devices Based on Terbium Complex

Rare earth complex Tb（BA）3phen was synthesized, which is first used as an emitting material in electroluminescence. The properties of monolayer device with the swing film rote of 1000 r·min^-1（70 nm） and the weight ratio of 1：5 （PVK：Tb（BA）3phen） are the best. And the highest brightness of this device reached 26.8 cd·cm^-2 at a fixed bias of 21 V. Bright green emission could be obtained from the optimized double-layer device and the highest EL brightness of the device reached 322 cd·m^-2 at the voltage of 22 V.

Synthesis,characteristic and intramolecular energy transfer mechanism of reactive terbium complex in white light emitting diode

A reactive Tb（III） complex with 2-aminobenzoic acid（2-ABAH） and acrylonitrile（AN） as ligands was synthesized.The structure of the complex was characterized by elemental analysis and Fourier transform infrared spectrometry（FT-IR）.The results indicated that the ligands were coordinated with Tb（III） ion.Thermal gravity-derivative thermogravimetric（TG-DTG） analysis indicated that the complex kept stable up to 198 oC.Luminescence properties were investigated by UV-vis absorption spectra and fluorescence spectra.The results suggested that being excited at 361 nm,the complex exhibited characteristic emission of Tb（III） ion,revealing that the complex could be excited by 365 nm ultraviolet chip.The HOMO and LUMO,ΔE（HOMO-LUMO）,molecular frontier orbital,and the singlet state and triplet energy state levels of the ligands were calculated at the B3LYP/6-31＋G（d） level.The results indicated that intramolecular energy transfer mechanism followed Dexter exchange energy transfer theory.Both the calculation for excited state of ligand and energy transfer mechanism could provide the theoretical basis for the design of high luminescent materials of rare earth complexes with organic ligands.

Crystal structure and properties of terbium o-methylbenzoate complex with 1,10-phenanthroline [Tb(o-CH_3C_6H_4COO)_3(C_(12)H_8N_2)]_2

A terbium o-methylbenzoate complex with 1,10-phenanthroline, Tb(o-MBA)_3phen(where o-MBA = o-methylbenzoate and phen = 1,10-phenanthroline) was prepared from ethanol solutionand its crystal structure was determined by X-ray diffraction. The crystal of the complexTb(o-MBA)_3phen belongs to triclinic crystal system and P1 (#2) space group. The crystal data are asfollows: a = 1.4371(4) nm, b = 1.7387(2) nm, c = 1.3109(2) nm, α = 96.37(1)°, β = 107.21(2)°,γ= 82.78(2)°, Ⅴ= 3.094(1) nm^3, Z= 2, M_r = 1489.12, D_c= 1.598 g·cm^(-3), μ = 2.330 mm^(-1)and F(000) = 1488.00. The final R and R_w are 0.038 and 0.047 for 8668 [Ⅰ > 2σ(Ⅰ)] uniquereflections, respectively. In the complex each Tb^(3+) ion is eight-coordinated by one1,10-phenanthroline molecule, one bidentate carboxylate group and four bridging carboxylate groups.The carboxylate groups are bonded to the terbium ion in two modes: the chelating bidentate and thebridging bidentate. Excitation and luminescence data observed at room temperature show that thetitle complex emits strong green fluorescence under ultraviolet light. The results of thermalanalysis indicate that the complex Tb(o-MBA)_3phen is quite stable to heat.

Synthesis, characterization and enhanced luminescence of terbium complexes with 2-pyrazinecarboxylic acid and butanedioic acid by inert-fluorescent lanthanide ions

Abstract： Ten solid terbium complexes with 2-pyrazinecarboxylic acid （Hpyca） and butanedioic acid （BDAH） were synthesized via coprecipitation method and characterized by elemental, EDTA titration, inductively coupled plasma （ICP）, thermogravim- etry-differential scanning calorimetry （TG-DSC） and infrared （IR） analyses. The results showed that the complexes had the composi- tions of Tb（pyca）（BDA）·2H2O, Tb0.5Y0.5（pyca）（BDA）·2H2O, Tb0.5La0.5（pyca）（BDA）·3H20, Tb0.5Gd0.5（pyca）（BDA）·2H2O, Tb0.7Y0.3（pyca）（BDA）·3HO, Tb0.7Lao.3（pyca）（BDA）-0.5H20, Tb0.TGd0.3（pyea）（BDA）＇H20, Tb0.6Y0.4（pyca）（BDA）·2.5H20, Tb0.6La0.4 （pyca）（BDA）·2.5H2O and Tbo.6Gd0.4（pyca）（BDA）·3H20. IR spectra indicated that the rare earth ions coordinated with the carboxylic oxygen atoms of Hpyca and BDAH. Luminescence spectra showed that the doped La3＋, y3＋ or Gd3＋ ions did not affect the lumines- cence emission peak positions, but remarkably increased the luminescent intensities of terbium complexes. Furthermore, the doped lanthanide complexes showed longer luminescence lifetimes and higher quantum yields than pure terbium complex. The enhanced luminescence efficiencies of Tb3＋ ions in the doped complexes might result from the antenna effect of the two carboxylate ligands as well as the decrease of the self-quench of the Tb3＋ ions induced by the doped lanthanide ions.

Syntheses of three terbium complexes as fluorescent probes and their application on the pH detection of routine urine test

By modifying the salicylic-acid moiety with electron-withdrawing or –donating groups, three new terbium complexes（LⅠ·Tb, LⅡ·Tb, L·（Ⅲ）Tb） based on tripodal carboxylate ligands were synthesized. Due to different pull-push electronic effects of ligands, the fluorescence intensities of these terbium complexes significantly varied, that is： LⅡ·Tb 〉L（Ⅲ）·Tb〉 LⅠ·Tb. Meanwhile, the characteristic peaks at 492 nm（5D4→7F6） and 547 nm（5 D4→7F5） showed ＂Off–On–Off＂ fluorescence response to various p H conditions,which indicated that all of them can be used as the highly sensitive pH fluorescent probes. Notably, using LⅡ·Tb with the best fluorescence performance as a probe, some patients＇ urine samples can be easily monitored through the response triggered by pH value. Therefore, LⅡ·Tb has the potential to auxiliarily diagnose some diseases in clinical practice through p H detection of routine urine test.

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 characterization of one-dimension complex constructed by terbium(Ⅲ) and 2-iodobenzoate

The complex of [Tb（2-IBA）3（H2O）2]n （2-IBA=2-iodobenzoate） was prepared by solvent method from TbCl3-6H2O and 2-iodobenzoic acid. The crystal structure was determined with X-ray single-crystal diffraction. The X-ray diffraction analysis indicated that the title complex crystallized in triclinic crystal system and Pi space group. The Tb^3＋ ion was coordinated by six oxygen atoms from five 2-IBA ligands and two oxygen atoms from two water molecules, giving a distorted square-antiprism polyhedral geometry. The carboxyl groups were bonded to the Tb^3＋ ions with bidentate-bridging and bidentate-chelating coordination modes. The adjacent Tb^3＋ ions were linked by two bidentate-bridging 2-IBA ligands, forming 1-D chain structure. The fluorescence spectrum of the complex showed four main peaks at 489, 543, 587, and 618 nm, corresponding to ^5D4→^7Fj（J=6-3） transition emissions of the Tb^3＋ ion, respectively.

Supramolecular Terbium-SIP Complex Pillared by 4,4'-Bipyridyl,{[Tb(SIP)(H_2O)_5]_2(bpy)_3(H_2O)}n:Synthesis,Crystal Structure and Photoluminescence

The supramolecular terbium complex, {[Tb（SIP）（H2O）5]2（bpy）3（H2O）}n （NaH2SIP = 5-sulfoisophthalic acid monosodium salt and bpy = 4,4＇-bipyridyl）, has been synthesized by the hydrothermal reaction of Tb4O7 with NaH2SIP and bpy at 165 ℃, and characterized by single-crystal X-ray diffraction, elemental analysis, IR spectrum, powder X-ray diffraction and photoluminescence spectrum. It crystallizes in a monoclinic system, space group C2/c, with a = 30.6840（1）, b = 10.9206（2）, c = 17.4967（3） A, β= 111.931（1）°, V = 5438.65（14） A^3, Z = 4, C46H52N6O25S2Tb2, Mr = 1470.90, Dc = 1.796 g/cm^3, p = 2.747 mm^-1, F（000） = 2928, the final R = 0.0654 and wR = 0.1322 for 3806 observed reflections with I 〉 2σ（I）. In the neutral [Tb（SIP）（H2O）5]2 motif, the Tb（III） ions are linked by the SIP ligands to form a one-dimensional zigzag chain propagating along the c axis. The zigzag chains are linked together by hydrogen bonds and π-π stacking interactions to form a two-dimensional supramolecular framework. The uncoordinated bpy molecules act as pillars to extend the two-dimensional sheets into a distinctive pillared three-dimensional supramolecular structure through O-H...N hydrogen bonds. The photoluminescence of the complex was investigated at room temperature in the solid state.

Characterization of luminescent hydroxyapatite@terbium complex core-shell composites using chlorobenzoic acid as ligands

Three kinds of novel hydroxyapatite@terbium complex core-shell composites were synthesized with 2-chlorobenzoic acid,4-chlorobenzoic acid,and 2,4-dichlorobenzoic acid as the ligand,respectively.The XRD,UV/vis absorption and FT-IR results show that terbium ions are coordinated with ligands and the corresponding complexes are successfully included into composites.SEM and EDS results reveal that Tb complexes are fully and homogenously coated on the surface of hydroxyapatite(HAP)microspheres consisting of a large number of nanosized crystals.The strongest luminescence properties are obtained when 2,4-dichlorobenzoic acid is used as ligand.The study on fluorescence lifetime of composites shows that the lifetime is inversely related to emission intensity.TGA-DSC results indicate that the core-shell composites have an excellent thermal stability.Therefore,the current core-shell structure provides a cost-effective route to manufacture of biocompatible and heatresistant highly luminescent materials.

Study on Photochemical Fluorescence Enhancement of Terbium-Fleroxacin Complex

The sensitized fluorescence intensity of terbium ion can be notably enhanced when the Tb 3+ fleroxacin complex is exposed to 365 nm light. By the measurements of fluorescence spectra, phosphorescence spectra, fluorescence quantum yield and fluorescence lifetime of the system, it is proved that irradiation makes the complex undergo a photochemical reaction and produces a new terbium complex which is more favorable to intramolecular energy transfer. The mechanism of the photochemical fluorescence enhancement was discussed.

Synthesis and Luminescence Properties of SBA-15 Functionalized with Covalently Bonded Terbium-Benzoic Acid Complex

Novel hybrid materials containing covalently bonded Terbium-benzoic acid complex in mesoporous silicaSBA-15 (denoted as Tb-SBA-15 ) were prepared via co-condensation of tetrethoxysilane (TEOS) and N-(4-benzoicacid-yl), N'-(propyltriethoxysilyl) urea (denoted as PABI).XRD, FTIR and luminescence spectroscopy were employed to characterize Tb-SBA-15.When monitored by the ligand absorption wavelength (270 nm), Tb-SBA-15 displays the emission of Tb3+ (5D4→7Fj (j = 6, 5, 4, 3 ) transition) due to the energy transfer from the ligands to Tb3+.

Highly efficient green organic light-emitting devices based on terbium complex by employing hole block material as host

In this work,efficient green electroluminescent（EL）devices with simplified device structure were prepared by doping trivalent terbium complex Tb（PMIP）3into hole block material Tm Py PB.The high triplet energy of Tm Py PB helps to confine excitons within light-emitting layer,while the electron transport characteristic of Tm Py PB facilitates the balance of carriers on Tb（PMIP）a3molecules.By optimizing the doping concentration of Tb（PMIP）a3and the thickness of each functional layer,highly efficient green EL device with the structure of ITO/Mo Oa3（3 nm）/TAPC（50 nm）/Tb（PMIP）a3（30 wt%）：Tm Py PB（25 nm）/Tm Py PB（60 nm）/Li F（1 nm）/Al（100 nm）displayed pure Tb^3＋ characteristic emission with maximum current efficiency,power efficiency and brightness up to 47.24 cd/A（external quantum efficiency（EQE）of 14.4%）,43.63 lm/W and 1694 cd/m^2,respectively.At certain brightness of 100 cd/m^2,the device still maintained a current efficiency of 19.96 cd/A（EQE=6.1%）.Such a device design strategy helps to improve the EL performances of Tb（PMIP）a3and to simplify device fabrication processes,thus reduce the fabrication cost.

Synthesis, Characterization and Fluorescence of Terbium(Ⅲ) Complexes with Phenylglyoxylic Acid and 2,2-Dipyridine, 1,10-Phenanthroline, Triphenyl Phosphine Oxide

Three new complexes TbL3dipy （H2O）2, TbL3phen （H2O） 2 and TbL2 （TPPO） 2NO3 were synthesized （L = phenylglyoxylate ion, dipy = 2, 2-dipyridine, phen = 1,10-phenanthmline, TPPO = Triphenyl phosphine oxide）. Elemental analysis, conductivity, IR spectra, and ^1HNMR spectra studies were performed. IR spectra indicate that the carboxylate ion of phenylglyoxylate is coordinated to the Tb（Ⅲ） ion as an unidentate ligand. In ^1HNMR, the signals of different hydrogens in phenylglyoxylate ion shift upfield. The excitation and emission spectra of the three solid complexes were recorded at morn temperature, in which the optimum excitation wavelengths are, 361.0, 359.0 and 367.0 nm for these three complexes, respectively. Four emission bands due to the ^5D4-^7Fj（j = 6, 5, 4, 3） transitions were observed for TbL3dipy（H2O）2（489.0, 545.0, 584.0, 620.0 nm） and TbL3phen（H2O）2（490.0, 544.0, 583.0, 620.0 nm）. Under the same conditions, only one emission band due to the ^5D4-^7F5 transition was observed for the complex TbL2（TPPO）2NO3. The emission intensity of TbL3dipy（H2O）2 is the strongest among the three complexes.