Terbium(III)-cholate functionalized vesicles as luminescent indicators for the enzymatic conversion of dihydroxynaphthalene diesters

The phosphorescence intensity of unilamellar DOPC vesicles with embedded Tb3+-cholate complexes depends on the concentration of dihydroxynaphthalene (DHN) as sensitizer in solution. This was used to monitor the enzymatic conversion of DHN esters or DHN glucosides by enzymes in aqueous buffered solution.

Synthesis and characterization of nano-scale Terbium (III)-trimesic acid (TMA)-1,10-phenanthroline(phen) luminescent complex

The nano-scale luminescent complex of Terbium(III)-trimesic acid (TMA)-1,10-phenanthroline(phen) was successfully synthesized by co-precipitation method in this paper. The chemical formula of the synthesized complex was speculated to be Tb(TMA)(phen)(0.0125)center dot 5H(2)O by elemental analysis, inductively coupled plasma-atomic emission spectroscopy (ICP-AES), and Fourier-transform infrared spectroscopy (FTIR). XRD pattern of Tb(TMA)(phen)(0.0125)center dot 5H(2)O indicated that it was a new crystalline complex since the diffraction angle, diffraction intensity and the distance of crystal plane were all different from those of the two ligands. TG curve proved that the synthesized nano-scale luminescent complex was stable in the range from ambient temperature to 464 degrees C in air. TEM images showed that the complex was spherical shape with an average size of 40 nm.

A novel terbium (III) beta-diketonate complex as thin film for optical device application

A novel terbium complex, Tb(acac)(3)AAP (acac: acetylacetone, AAP: 4-amino-antipyrine), was synthesized and its luminescent properties were studied. When it was used as an emitting center, triple-layer-type device with a structure of glass substrate/ITO (indium-tin oxide)/TPD (N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine)./Tb(acac)(3)AAP/PBD (2-(4-biphenyl)-5-(4-t-butylphenyl)-1,3,4-oxadiazole) or Alq(3) (tris(8-hydroxyquinolinato) aluminum)/Al (aluminum) exhibited bright characteristic emission of terbium ion upon applying d.c. voltage. The maximum luminance of the device is 56 cd/m(2) at 19 V and the maximum luminance efficiency is 0.357 lm/W.

The preparation and property studies of transparent resins containing rare earth terbium(III) complex

The binary and ternary rare-earth terbium(m) complexes were introduced into the styrene/alpha -methylacrylic acid copolymerization system, and some optical resins that possess a high transparency in visible light region were obtained. The study of the optical property showed that they have good luminescent properties such as a high luminous intensity and a long luminous lifetime, In addition, we investigated the relationship among the transparency, the luminescent property of the copolymer, and the content of the components in the polymeric system. The results indicated that the optical resins can provide a relatively stable environment for composite rare earth complexes, which is good to exhibit the luminescent properties of rare earth complexes. At the same time, the rare earth complexes can offer the transparent resin a novel function.

Lanthanide coordination polymers with dicarboxylate-like ligands: crystal structures of polymeric lanthanum(III) and terbium(III) complexes with flexible double betaines

Four novel polymeric lanthanide(III) complexes of two new double betaine derivatives have been synthesized and structurally determined. In [{La-2(L-1)(2)(H2O)(9)}(n)]Cl-6n. 2nH(2)O (1) and [{Tb(L-1)(H2O)(4)}(n)]Cl-3n. nH(2)O (2) (L-1 =4,4'-trimethylenedipyridinio-N,N'-diacetate), the lanthanide(III) ions form a two-dimensional layer in which each pair of lanthanide(III) ions is bridged by two syn-anti mu-carboxylato-O,O' groups. Adjacent layers are cross-linked through hydrogen bonds among aqua ligands, lattice water molecules and chloride ions, to form a three-dimensional network. Isomorphous [{Ln(L-1)(H2O)(4)}(n)]Cl-3n. 5nH(2)O (Ln=La, 3; Ln=Tb, 4; L-2=1,3 bis(pyridinio-4-carboxylato)-propane) each contain a centrosymmetric paddle-wheel-like dimeric unit in which each pair of adjacent metal atoms is bridged by four syn-syn mu-carboxylato-O,O' groups that are oriented nearly perpendicular to each other about the metal-metal axis. Neighboring dimeric subunits are bridged by a pair of flexible LL ligands into a polymeric chain. Adjacent chains are inter-linked by hydrogen bonds among aqua ligands, lattice water molecules and chloride ions into a three-dimensional network. (C) 1999 Elsevier Science Ltd. All rights reserved.

Observations on photochemical fluorescence enhancement of the terbium(III) sparfloxacin system

Fluorescence of terbium(III) was sensitized when excited in the presence of sparfloxacin (SPFX) in the aqueous solution because a Tb(III)-SPFX complex was formed. The sensitized fluorescence was further enhanced when this system was exposed to 365 nm ultraviolet light. By the spectral properties and contrast experiments, it is proved that irradiation makes this system undergo photochemical reactions and a new terbium complex which is more favorable to the intramolecular energy transfer is formed. The mechanism of photochemical fluorescence enhancement of the Tb(III)-SPFX system is discussed and a new sensitive and selective photochemical fluorimetry for the determination of SPFX is established. Under the optimum conditions, the linear range is 1.0-50 x 10(-7) M for SPFX, the detection limit is 3.0 x 10(-9) M and the R.S.D. for 5.0 x 10(-7) M SPFX is 1.3% (n = 9). Without any pretreatment the recovery of SPFX in human urine was determined with satisfaction. (C) 1999 Elsevier Science B.V. All rights reserved.

Luminescence properties of the Langmuir-Blodgett film of terbium(III) stearoylanthranilate

Terbium(III) stearoylanthranilate has been prepared as a high property Z-type Langmuir-Blodgett (LB) film on various substrates by a vertical transfer process. The UV-visible absorption spectra and the low angle X-ray diffraction peaks have been collected in order to investigate the molecular arrangement and aggregation in the LB films. The average molecular orientation in multilayer stacking was determined by Attenuated Total Reflection Spectroscopy. The influence of the chemical environment of terbium within the LB films on the luminescence properties has been discussed. (C) 1997 Elsevier Science S.A.

SOLVENT-EXTRACTION OF TERBIUM(III,IV) PERIODATE COMPLEXES WITH QUATERNARY AMINE

The differences between the solvent extraction of Tb(III) and Tb(IV) periodate complexes with quaternary amine were studied carefully for the first time. The effects of extractant concentration, phase ratio, the pH value of stock solution, salting-out agent, extractant form, diluent, and extraction time were comprehensively investigated. Under optimal conditions the separation factor between Tb(IV) and Tb(III) periodate complexes is over 5.5.

Sensitized terbium(iii) macrocyclic-phthalimide complexes as luminescent pH switches

Four new macrocyclic-phthalimide ligands were synthesised via the coupling of N-(3-bromopropyl)phthalimide either to cyclen (1,4,7,10- tetraazacyclododecane) itself or its carboxylate-functionalized analogues, and photophysical studies were carried out on their corresponding Tb(iii) complexes in aqueous media as a function of pH. Luminescence intensities of Tb·L^1a-Tb·L^3a were in 'switched off' mode under acidic conditions (pH < 4), and were activated on progression to basic conditions as the phthalimido functions therein were hydrolysed to their corresponding phthalamates Tb·L^1b-Tb·L^3b. Emission of phthalamate-based macrocyclic Tb(iii) complexes Tb·L ^1b-Tb·L^3b was in 'switched on' mode between pH 4 and 11, exhibiting high quantum yields (Φ) and long lifetimes (τ) of the order of milliseconds at pH ∼ 6. Tb(iii) emissions were found to decline with increasing number of chromophores. The values of Φ and τ were 46% and 2.4 ms respectively for Tb·L^1b at pH ∼ 6 when activated. This is the best pH-dependent sensor based on a Tb(iii) complex reported to date, benefiting from the macrocyclic architecture of the ligand. © 2013 The Royal Society of Chemistry.

Fluorescence study of the interaction between metal ions and methyl methacrylate methacrylic acid copolymers in aqueous solutions: thallium(I), calcium(II), and terbium(III)

The binding of the cations thallium(I), calcium(II) and terbium(III) to methyl methacrylate-methacrylic acid copolymers with different fractions of acid groups (x) has been studied in aqueous solution at, various pH values using the fluorescence of covalently bonded 9-vinyl anthracene as a probe. In all cases, the extent of binding increases as a function of the charge of the polymer with either increasing fraction of carboxylic acids or of pH. However, differences are observed in the behavior of the three cations, With Tl(I), quenching of the anthracene group fluorescence is observed. indicating that the thallium(I) approaches the probe and suggesting that the alkylanthracene is probably in a relatively polar region. Binding constants have been determined from anthracene quenching data and from studies with the fluorescent-probe sodium pyrenetetrasulfonate, Good agreement is obtained between the two methods, and values for the binding constants increase from 250 to 950 M-1 as x increases from 0.39 to 1. It is suggested that the cation is held in the polyelectrolyte domain, partly by Debye-Huckel effects and partly by more specific interactions. Stronger binding is found with calcium(II) and terbium(III), and in this case increases in fluorescence intensity are observed on complexation due to the anthracene group being in a more hydrophobic region, probably as a result of conformational changes in the polymer chain. In the former case the stoichiometry of the interaction was determined from the fluorescence data to involve two carboxylate groups bound per calcium. Association constants were found using murexide as an indicator of free calcium to vary from 8400 to 37 000 M-1 as x increases from 0.39 to 1. It is suggested that in this case specific calcium(II)-carboxylate interactions contribute to the binding. With terbium(III), a greater increase in the probe fluorescence intensity was observed than with calcium, and it is suggested that the interaction with the polymer is even stronger, leading to a more pronounced conformational change in the polymer. It is proposed that the terbium(III) interacts with sis carboxylic groups on the polymer chain, with three being coordinated and three attracted by electrostatic interactions.

Synthesis and thermal characterization of luminescent powers of terbium(III) with mixed ligands

This work deals with the synthesis and thermal decomposition of complexes of general formula: Ln(beta-dik)(3)L (where Ln=Tb(+3), beta-dik=4,4,4-trifluoro-1-phenyl-1,3butanedione(btfa) and L=1,10-fenantroline(phen) or 2,2-bipiridine(bipy). The powders were characterized by melting point, FTIR spectroscopy, LTV-visible, elemental analysis, scanning differential calorimeter(DSC) and thermogravimetry(TG). The TG/DSC curves were obtained simultaneously in a system DSC-TGA, under nitrogen atmosphere. The experimental conditions were: 0.83 ml.s(-1) carrier gas flow, 2.0 +/- 0.5 mg samples and 10 degrees C.min(-1) heating rate. The CHN elemental analysis of the Tb(btfa)(3)bipy and Tb(btfa)(3)phen complexes, are in good agreement with the expected values. The IR spectra evinced that the metal ion is coordinated to the ligands via C=O and C-N groups. The TG/DTG/DSC curves of the complexes show that they decompose before melting. The profiles of the thermal decomposition of the Tb(btfa)3phen and Tb(btfa)3bipy showed six and five decomposition stages, respectively. Our data suggests that the thermal stability of the complexes under investigation followed the order: Tb(btfa)(3)phen < Tb(btfa)(3)bipy.

Terbium(III) and dysprosium(III) 8-connected 3D networks containing 2,5-thiophenedicarboxylate anion: Crystal structures and photoluminescence studies

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Terbium(III) and dysprosium(III) 8-connected 3D networks containing 2,5-thiophenedicarboxylate anion: Crystal structures and photoluminescence studies

Two novel coordination polymers with the formula {[Ln(2)(2,5-tdc)(3)(dmso)(2)].H2O}(n) (Ln = Tb(III) for (1) and Dy(III) for (2)), (2,5-tdc(2-) = 2,5-thiophenedicarboxylate and dmso = dimethylsulfoxide) have been synthesized by the diffusion method and characterized by thermal analysis, vibrational spectroscopy and single crystal X-ray diffraction analysis. Structure analysis reveals that 2,5-tdc(2-) play a versatile role toward different lanthanide ions to form three-dimensional metal-organic frameworks (MOFs) in which the lanthanides ions are heptacoordinated. Photophysical properties were studied using excitation and emission spectra, where the photoluminescence data show the high emission intensity of the characteristic transitions D-5(4 ->) F-7(J) (J= 6, 5, 4 and 3) for (1) and (F9/2 -> HJ)-F-4-H-6 (J = 15/2, 13/2 and 11/2) for (2), indicating that 2,5-tdc(2-) is a good sensitizer. (C) 2012 Elsevier Ltd. All rights reserved.