Luminescent properties of europium(III) and terbium(III) complexes with para- and ortho-ethoxybenzoic acids

The luminescent properties of europium(III) and terbium(III) complexes with para- and ortho-ethoxybenzoic acids are studied. The excitation energies of the triplet states of ligands are determined, a hypothesis is made about the efficient luminescence of europium(III) and terbium(III) complexes, the geometry of the coordination polyhedron of a europium complex is established, and the luminescence quantum yields of the complexes in solution are determined.     

Synthesis of 1,3-diketo derivatives of calix[4]arene with nonyl substituents at the lower rim as novel efficient sensibilizers of Tb<Superscript>3+</Superscript> luminescence

Novel bis- and tetra-1,3-diketo derivatives of calix[4]arene with nonyl substituents at the lower rim have been synthesized. Their conformational and tautomeric composition have been determined; spectral parameters and complex formation properties with Tb³⁺ have been studied. Substitution of two 1,3-diketo groups with bromine under going from tetra- to bis 1,3-diketone derivatives was resulted in twofold increase luminescence intensity in their terbium complexes. Lifetime of the excited state of the terbium luminescence of the corresponding complexes as well as lifetime of excited triplet level of the 1,3-diketonate ligands have been determined.     

Simultaneous spectrophotometric determination of atrazine and cyanazine by chemometric methods

Three novel ligands containing pyridine-2,6-dicarboxylic acid unit, trans-4 -(4'-methoxystyryl) pyridine-2,6-dicarboxylic acid, trans-4-(4'-(dimethylamino)styryl)pyridine-2,6-dicarboxylic acid, and trans-4-(4'-(diphenylamino)styryl)pyridine-2,6-dicarboxylic acid were synthesized and their complexes with Eu(III), Tb(III) ions were successfully prepared. The ligands and the corresponding metal complexes were characterized by means of MS, elemental analysis, IR, (1)H NMR and TG-DTA. The luminescence spectra of Eu(III) and Tb(III) complexes in solid state were studied. The strong luminescence emitting peaks at 615 nm for Eu(III) and 545 nm for Tb(III) can be observed. The applications in cell imaging of the europium and terbium complexes were investigated.     

Luminescense properties of new complexes of Eu(III) and Tb(III) with heterotopic ligands

As a result of coordination between ligands L and L' and europium(III) and terbium(III) ions, the new architectures were formed. The formulae of the complexes have been assigned on the basis of the spectroscopic data in solution and microanalyses. The europium complexes show excellent luminescence properties with high quantum yield (1b-Eu(3)L(2)) and effective intramolecular energy transfer from the ligand to the Eu(III) ions.     

IR Luminescence of Nd<Superscript>3+</Superscript>, Sm<Superscript>3+</Superscript>, and Yb<Superscript>3+</Superscript> β-Diketonates in Different Aggregate States

The influence of the aggregate state on the IR luminescence is studied for the Nd(III), Sm(III), and Yb(III) complexes with the thienyl, phenyl, and alkyl derivatives of acetylacetone in solutions and as sorbates on the polymer matrix. It is found that the luminescence intensity of the sorbates of the complexes is 2–3 orders of magnitude higher than that in solutions due to the elimination of diffusion and respective intermolecular nonradiative losses of the excitation energy.     

Synthesis,characterization and luminescence properties of Eu(III) and Tb(III) complexes with novel pyrazole derivatives and 1,10-phenanthroline

Two novel pyrazole-derived ligands, 3-chloro-6-(3,5-dimethyl-1H-pyrazol-1-yl)picolinic acid (CDPA) and 3-chloro-6-(3,5-dimethyl-1H-pyrazol-1-yl)-N-phenylpicolinamide (CDPP) were prepared by 3,6-dichloropicolinic acid (DCPA). Their complexes with terbium(III) and europium(III) were synthesized. The complexes were characterized by elemental analysis, infrared spectra, ¹H NMR and TG–DTG. Furthermore, the above complexes using 1,10-phenanthroline as a secondary ligand were also synthesized and characterized. The luminescence properties of these complexes in solid state were investigated. The results suggested that Tb(III) complexes exhibit more efficient luminescence than Eu(III) complexes and the fluorescence of the complexes with 1,10-phenanthroline as a secondary ligand was prominently stronger than that of complexes without this ligand., and the three ligand (DCPA), (CDPP) and (CDPA) are excellent sensitizers to Eu(III) and Tb(III) ion.     

The study on the effect and mechanism of the second ligands on the luminescence properties of terbium complexes

The binary complex of Tb(III) with N-phenylanthranilic acid (N-HPA) was synthesized, and the ternary complexes were synthesized by introducing 1,10-phenanthroline (Phen), 2,2'-dipyridyl (Bipy), trioctylphosphine oxide (TPPO) as the second ligand, respectively. These complexes were characterized by infrared spectra, UV spectra and fluorescence spectra. The effect and mechanism of different second ligands on the fluorescent intensity of the terbium N-phenylanthranilic acid complexes was discussed. It showed that all the complexes exhibited ligand-sensitized green emission. The luminescence intensity increased in the sequence of Tb(N-PA)(3)Phen相似文献   

Distribution of luminescence excitation energy between Eu<Superscript>3+</Superscript> and Tb<Superscript>3+</Superscript> ions fixed in a perfluorosulfonic membrane

Ion-exchange modification of MF-4SK perfluorosulfonic membranes with Eu³⁺ and Tb³⁺ cations was realized. The state of cations in the membrane was studied by X-ray photoelectron spectroscopy. Special features of the luminescence of the resulting systems point to preferential excitation energy transfer from europium to terbium.     

Synthesis and Luminescent Properties of Terbium(III) and Europium(III) Fluoride Nanoparticles Modified with Aromatic Carboxylic Acids

Europium(III) and terbium(III) fluoride nanoparticles modified with citric, anthranilic, benzoic, salicylic, and acetylsalicylic acids have been obtained by means of sorption from solution and modification in statu nascendi. The shape and size of the particles have been determined by scanning electron microscopy. The luminescence of the samples was studied and it has been established that terbium fluoride nanoparticles modified with acetylsalicylic acid exhibits the highest luminescence intensity.     

A new luminescence method for determining dysprosium in the presence of terbium

The new luminescence method for determining dysprosium in the presence of terbium is developed based on the difference in the lifetimes of dysprosium and terbium in complexes with 3-(6-benzodioxanyl)pyrazole-5-carboxylic acid (τ = 6 and 910 μs, respectively). The possibility of determining the short-lived and weakly luminescent dysprosium(III) ion in the presence of long-living and intensively luminescent terbium(III) was demonstrated for the first time using time-resolved luminescence. The developed method was used to determine dysprosium in luminescent materials doped with both lanthanides.     

The role of copper ions in Tb(III) luminescence sensitization in heterometallic complexes with podands

It has been demonstrated that copper-induced terbium(III) luminescence sensitization in heterometallic complexes with hydrazine-containing podands is caused by the ligand ring closure and joint coordination of both metal ions to the carbonyl oxygen atoms as well as, mainly, by the reduction with the hydrazine substituents of Cu(II) to Cu(I), which is able to sensitize terbium luminescence.     

Complex compounds of terbium(III) with some nonsteroidal anti-inflammatory drugs and their analytical applications

Luminescence properties of the complexes of terbium(III) with nonsteroidal anti-inflammatory drugs (ibuprofen and orthofen) were studied. It was demonstrated that in the presence of organic bases (2,2’-dipyridyl and 1,10-phenanthroline) mixed-ligand complexes are formed and the luminescence intensity of terbium(III) increases by a factor of up to 250. The optimum complexation conditions were determined. It was proposed to use these complexes as analytical forms for the luminescence determination of nonsteroidal anti-inflammatory drugs (ibuprofen and orthofen) in pharmaceutical dosage forms. The detection limits are 2 and 0.05 μg/mL, respectively.     

Synthesis and infrared and fluorescence spectral properties of luminescent terbium and europium complexes with open-chain carboxylate crown ethers

Two open-chain carboxylate crown ether ligands and their terbium(III) and europium(III) complexes were synthesized and characterized. The terbium and europium ions were found to coordinate to the carboxylate oxygens. The fluorescence properties of europium complexes in the solid state and terbium complexes in the solid state and in the organic solvent were studied in detail, respectively. Under the excitation of ultraviolet light, strong green fluorescence of solid terbium complexes and red fluorescence of solid europium complexes were observed. These observations show that the two ligands favor energy transfer to the emitting energy level of Tb(3+). Some factors that influencing the fluorescent intensity were also discussed.     

Conformation effects on the fluorescence spectra of europium and terbium complexes with a family of ether-amide type multipodal ligands

Three multipodal ligands: 3,3,7,7-tetra[N-methyl-N-phenyl(acetamide)-2-oxymethyl]-5-oxanonane (La), 3,3,7,7-tetra[N-ethyl-N-phenyl(acetamide)-2-oxymethyl]-5-oxanonane (Lb), 3,3,7,7-tetra[N-benzyl-N-phenyl(acetamide)-2-oxymethyl]-5-oxanonane (Lc) and their europium and terbium nitrate and perchlorate complexes were synthesized. The 12 complexes were characterized by elemental analysis, IR, fluorescence spectroscopy and conductivity. The novel cup-like crystal structure of the Eu(III) complex with Lb and fluorescence emission properties of the complexes have also been studied. It has been showed that the nature of the anion has a great effect upon the composition of the complexes. The difference in the composition of the complexes results in the difference in the emission properties of them. The [Ln(NO3)5] group is negatively effective to the fluorescence intensity of the nitrate complexes. The luminescence intensity of Ln(III) perchlorate complex is stronger than that of nitrate complex.     

Europium(III) and terbium(III) chelates of quinolonecarboxylic acid derivatives as labels for immunofluorimetric assay

Luminescence properties of Tb(III) and Eu(III) complexes of quinolonecarboxylic acid derivatives were studied. Optimal conditions of luminescence were determined, and the influence of surfactants and diethylenetriaminepentaacetic acid on the luminescence properties of the complexes was studied. It was demonstrated that species-specific immunoglobulins labeled with terbium ions can be determined with the detection limit of the lanthanide label 5 x 10^-14 M.     

Luminescence determination of DNA using terbium complexes with 2-oxo-4-hydroxyquinoline-3-carboxylic acid amides as probes

It was found that the presence of DNA significantly enhanced the 4f luminescence of terbium(III) in its complexes with a number of 2-oxo-4-hydroxyquinoline-3-carboxylic acid amide derivatives (L₁-L₆). For the high-sensitivity determination of DNA, L₁ and L₄ were chosen from two proposed groups, in complexes with which terbium ions exhibited the most intense luminescence. Under optimum conditions, the luminescence intensity of terbium was proportional to the concentration of DNA over the ranges 0.025–1.2 μg/mL (detection limit of 10 ng/mL) and 0.01–1.2 λg/mL (detection limit of 3 ng/mL) for L₁ and L₄, respectively. The mechanisms of the interaction of Tb-L complexes with DNA molecules were hypothesized.     

稀土N-苯基邻氨基苯甲酸-1,10-邻菲咯啉二元、三元配合物的合成、表征及其光物理性质

合成了几种新型的稀土(钆,铕,铽)的N-苯基邻氨基苯甲酸-1,10-邻菲咯啉的二元、三元配合物.以元素分析、红外光谱和紫外光谱进行了表征,确定了组成.同时以低温磷光光谱确定了配体的三重态能级为24330cm^-1,研究了配体与稀土离子的能级匹配.详细讨论了配合物的光物理性质如发光性能和配体与稀土离子之间以及有机配体之间的分子内能量传递机制,结果发现,铽的N-苯基邻氨基苯甲酸-1,10-邻菲咯啉配合物的发光性能良好.     

Spectral-luminescence and magnetic relaxation properties of lanthanide—<Emphasis Type="Italic">p</Emphasis>-sulfonatothiacalix[4]arenes in aqueous solution of surfactants

The influence of nonionogenic, anionic and cationic surfactants on the magnetic relaxation and luminescence properties of gadolinium(III), terbium(III), and dysprosium(III) complexes with p-sulfonatothiacalix[4]arene (TCAS) was studied. It was shown that the presence of both neutral and anionic surfactant does not influence the magnetic relaxation properties of GdTCAS as well as on the luminescence intensity of the TbTCAS and DyTCAS complexes. The presence of cationic surfactant at the concentration less than critical micellar concentration led to the formation of associates with stoichiometric composition with the Tb (Dy, Gd) TCAS complexes. These associates are characterized by more intensive luminescence, as compared to the initial TbTCAS and DyTCAS complexes. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 555–560, March, 2008.     

Innovative Multipodal Ligands Derived from Tröger's Bases for the Sensitization of Lanthanide(III) Luminescence

Herein, the synthesis and characterization of the first family of multipodal ligands with a Tröger's base framework designed for the preparation of luminescent lanthanide(III) complexes are reported. Eight ligands were designed and synthesized using different strategies, including alkylation reactions, amide couplings, and Ugi multicomponent reactions. All the ligands bear carboxylate groups for the coordination of the lanthanide(III) ions, with the lanthanide(III)-sensitizing units consisting of the Tröger's base framework itself or attached benzamides. Upon irradiation of the chromophoric ligands, green terbium(III) emission was efficiently generated, whereas europium(III) emission was negligible. The geometry and substitution pattern of the ligands allow control of the stoichiometry of the species formed and the Tb^III luminescence sensitization efficiency, showing that para-substitution patterns are more efficient than meta substitution for the formation of coordination compounds with lower Tb^III/ligand ratio. We propose that the species formed are self-assembled 2:2 or 2:4 metallosupramolecular structures.     

Synthesis and Photochemical Properties of Luminescent Eu(III) Complexes with Macrocyclic and Macropolycyclic Ligands Incorporating 3,3′-Biisoquinoline-2,2-dioxide Units

Three novel ligands incorporating two, or three 3,3-biisoquinoline-2,2-dioxide units have been synthesized using modified standard methods of cyclization. These ligands formed photoactive mononuclear complexes with a Eu(III) cation. The ligand with two photoactive units displayed a better quantum yield for the Eu(III) emission (0.064) upon UV excitation than the other two complexes incorporating three units, whose luminescence quantum yields have been estimated to be below 0.01. The luminescence of the Eu(III) complex with two sensitizing units was not stable in aqueous solution, whereas with the two other complexes, their luminescence in solution remained for a couple of days.