Complexation and the laser luminescence studies of Eu(III), Am(III), and Cm(III) with EDTA,CDTA, and PDTA and their ternary complexation with dicarboxylates

Spectroscopy has been used to determine the number of coordinated water molecules bound to Eu(III) and Cm(III) in a series of binary complexes of polyaminocarboxylate and their ternary complexes with dicarboxylates as well as with similar ligands with additional O-, N-, and S-donors. Complexes of Eu(III) and Cm(III) with polyaminocarboxylate alone contain ca. 2.5–3.0 waters of hydration. Increasing the steric requirement of a polyaminocarboxylate by increasing the number of groups in the ligand backbone does not appreciably change the hydration of these cations. The stability constants of the binary and ternary complexes of Cm(III), Am(III), and Eu(III) with these ligands were measured by solvent extraction in a solution of 0.1 M (NaClO₄). The size, basicity, specific M³⁺-second ligand interactions, and steric requirement of the ligands are the factors which affect the ternary complexation. Knowledge of the chemical species formed by actinide cations with organic ligands (carboxylates and aminocarboxylates), which are present in all nuclear waste, is important to understand the behavior of waste forms and the migration behavior of actinides in the environment.     

Quantum efficiency of the luminescence of Eu(III), Tb(III) and Dy(III) in aqueous solutions

Summary The luminescence quantum efficiency of Eu(III), Tb(III) and Dy(III) in chloride solutions as well as complexed by aminopolyacetic acids was determined. An interpretation of the observed dependences in the system investigated has been proposed.

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Die Lumineszenz-Quantenausbeute von Eu(III), Tb(III) und Dy(III) in wäßrigen Lösungen

Zusammenfassung Die Lumineszenz-Quantenausbeute von Eu(III), Tb(III) und Dy(III) in Chloridlösung und in Komplexen mit Aminopolyessigsäuren wurde bestimmt. Eine Interpretation der beobachteten Abhängigkeiten im untersuchten System wurde vorgeschlagen.

     

Synthesis and photophysical properties of colloids fabricated by the layer-by-layer polyelectrolyte assembly onto Eu(III) complex as a core

The luminescent colloids have been synthesized through the layer-by-layer assembly of poly(sodium 4-styrenesulfonate) (PSS) and polyethyleneimine (PEI) onto the luminescent core. The latter has been obtained by the reprecipitation of complex Eu[(TTA)(3)1] (where TTA(-) and 1 are thenoyltrifluoroacetonate and 2-(5-chlorophenyl-2-hydroxy)-2-phenylethenyl-bis-(2-methoxyphenyl)phosphine oxide, respectively) from organic solvent to aqueous solution. The variation of Eu(III) complexes indicates the role of the complex core in the development of such core-shell colloids. Complex Eu[(TTA)(3)1] is most convenient precursor of Eu-doped luminescent nanocomposites. The fluorometric measurements at each step of the layer-by-layer polyelectrolyte assembly onto Eu[(TTA)(3)1] core, at various pHs and additives reveal the quenching of Eu-centered luminescence as a result of the interfacial interaction of the core and the dye. The AFM images and electrochemical behavior of PSS-(PEI-PSS)(n)-Eu[(TTA)(3)1] colloids deposited on the surface indicate the stability of the polyelectrolyte multilayer in the dried state.     

The Study on the Stability Constant and Species Distribution of Eu (III) and Tb (III) Complexes with BDBPH

Biomimetic hydrolysis of DNA or RNA is of increasing importance in biotechnology and medicine. The ability to cleave nucleic acids efficiently, in a non-degradative manner, and with high levels of selectivity for site or structure will be required by many applications for the manipulation of genes, the design of structural probes and the development of novel therapeutics1. There has been much interest in the development of lanthanide complexes as nucleic acid cleavage agents. It has been fou…     

Antimicrobial,antioxidant and antitumor activities of Nano-Structure Eu (III) and La (III) complexes with nitrogen donor tridentate ligands

Nano structure metal complexes of Eu (III) and La (III) with two different nitrogen donor tridentate ligands: N-(2-Aminoethyl)-1,3-propanediamine “AEPD = L1” and 1-(2-Aminoethyl)piperazine “AEPz = L2” , were prepared. All synthesized compounds were identified and confirmed by elemental analyses, molar conductivity and spectral analyses (UV–Visible, IR and mass). Conductance measurement indicates that all the complexes are non-electrolytic in nature and the complexes were isolated in 1:1 molar ratio (metal: ligand). Thermal decomposition profiles were consistent with the proposed formulations. The ligands behave as a tridentate ligand through three nitrogen centers of donation. The nano-size was investigated by using transmission electron microscopy (TEM). The geometric structure properties were analyzed using density functional theory (DFT) for ligands and their Lanthanum (III) complexes. The complexes were screened against some bacteria strains, hepatocellular cell line and diphenylhydrazine free radical. The molecular docking active sites interactions were evaluated.     

Eu3+,Tb3+混配配合物的激光诱导荧光

利用激光诱导荧光技术研究了两种三价稀土金属离子的β－二酮与有机配体混配络合物中金属离子的寿命及其能级结构，得到了Ｅｕ＾３＋的能级常数。     

Luminescence and energy transfer in poly(N-vinylcarbazole) blends doped by a highly anisometric Eu(III) complex

Highly fluorescent blends based on PVK (poly(N-vinylcarbazole)) doped by a new greatly anisometric Eu(III) mesogenic complex were described. The structure of the ligands in the complex was selected in such a way that its absorption maximum was close to the emission maximum of the polymer. The full-energy transfer conditions in the conjugated polymer–lanthanide complex blends were revealed. Improving luminescence efficiency of the blend occurs due to an increase in the threshold concentration of the emitting ions to prevent self-quenching phenomena. The resulting relative luminescence quantum yield of the blend increases more than twice in comparison with the individual complex. The optimized blends may be promising for application as red emitters for OLED, etc.     

一种双核铕配合物的合成、光致发光和电致发光性质研究

合成了一个新的双核铕配合物Eu(TTA)₃(tpphz)Eu(TTA)₃(其中TTA＝去质子化的α-噻吩甲酰三氟丙酮; tpphz＝[3,2-a:2',3'-c:3',2'-h:2'',3''-j]四吡啶基吩嗪). 研究了该配合物的光致发光和电致发光性质. 一个四层电致发光器件ITO/TPD, 10 nm/Eu(TTA)₃(tpphz)Eu(TTA)₃, 20 nm/BCP, 20 nm/AlQ, 40 nm/Mg_0.9Ag_0.1, 200 nm/Ag, 100 nm表现出中心在633 nm处的宽带红光发射, 该宽带发射可能来源于双核Eu(III)配合物和TPD形成的激基复合物. 该器件的启动电压为10 V, 在18 V和135 mA/cm²时的最大亮度达146 cd/m².     

Cationic complexes of Eu(III) and Sr(II) with diphosphine dioxides in organic extracts

IR spectroscopy was used to study the structure and composition of Eu(III) and Sr(II) complexes formed by cation-exchange extraction of these metals from their aqueous nitrate solutions with dichlorethane solutions of mixtures of chlorinated cobalt(III) dicarbollide (CCD) as a superacid with diphenyldiphosphine dioxides containing a methyl (Me-DPDO), ethyl (Et-DPDO), or polyoxyethylene bridge between two phosphorus atoms of phosphine oxide groups. At molar ratios DPDO/CCD ≤ 1, [Eu(H₂O)_nL₄]³⁺ complexes are formed in organic phases, whereas with an excess of DPDO relative to CCD, Eu(NO₃)L ₄ ²⁺ complexes are formed, where L = Me-or Et-DPDO. Polyoxyethylenediphosphine dioxide forms anhydrous complexes of composition Eu:L = 1:1 and 1:2 with Eu(III) and outer-spheric complexes of composition Sr:L = 1:1 and 1:2 with Sr(II), where the organic ligand molecules envelop the hydrated Sr(H₂O) _n ²⁺ cation. The peculiarities of extraction of the complexes are explained based on data about their composition and structure.     

含联吡啶，Eu(III)或Gd(III)的手性高分子配合物的合成及荧光性质研究

手性高分子P–1由(R)-5,5′-二溴-6,6′-二(4-三氟甲基苯基)-2,2′-二正辛氧基-1,1′-联萘(R–M–1)和5,5′-二乙烯基-2,2′-联吡啶(M–2)通过Pd催化的Heck偶合反应合成得到,高分子配合物P-2和P-3由高分子P-1与Eu(TTA)3·2H2O和Gd(TTA)3·2H2O (TTA– = 2-噻吩甲酰三氟丙酮)反应生成。手性高分子P-1能发射强的蓝色荧光,这是由于手性重复单元(R)-6,6′-二(4-三氟甲基苯基)-2,2′-二正辛氧基-1,1′-联萘和单元2,2′-联吡啶通过亚乙烯基桥连形成共轭高分子结构造成的。在不同的激发波长激发下,含Eu(III)的高分子配合物P–2不仅显示高分子荧光,还可显示Eu(III) (5D0→7F2)特征荧光。含Gd(III)的高分子配合物P–3仅发射高分子荧光。基于高分子及含RE(III)的高分子配合物的荧光性质研究发现,共轭高分子并没有把能量转移到Eu(III)或Gd(III) 配合物部分,只发射它自身的荧光,含Eu(III)的高分子配合物P–2发射Eu(III) (5D0→7F2)特征荧光能量主要来源于配阴离子TTA–。     

Facilitated transport of Am(III) through a flat-sheet supported liquid membrane (FSSLM) containing tetra(2-ethyl hexyl) diglycolamide (TEHDGA) as carrier

Facilitated transport of Am(III) in nitric acid medium using tetra(2-ethyl hexyl) diglycolamide (TEHDGA) in n-dodecane as carrier was studied. It was aimed at finding out the physico-chemical model for the transport of Am(III) using TEHDGA/n-dodecane as carrier under various experimental parameters like feed acidity, carrier concentration, varying strippant, varying membrane pore size, etc. The feed acidity and carrier concentrations were varied from 1 M to 6 M HNO₃ and 0.1 M to 0.3 M TEHDGA/n-dodecane, respectively. The transport of Am(III) increased with increase in feed acidity and carrier concentration reaching maximum at 3 M HNO₃ and 0.2 M TEHDGA/n-dodecane, respectively. Several stripping agents were tested and 0.1 M HNO₃ was found to be the most suitable stripping agent for this system. Almost quantitative transport of Am(III) was observed at about 180 min with feed acidity of 3 M HNO₃, 0.1 M HNO₃ as strippant and 0.2 M TEHDGA/n-dodecane as carrier. The pore size of the membrane support was varied from 0.20 μm to 5 μm and the permeation coefficient increased with increase in pore size up to 0.45 μm (2.43 × 10⁻³ cm/s), and then decreased with further increase in pore size. The plot between permeation coefficient vs. (membrane thickness)⁻¹ was linear which showed that the Am(III) transport was membrane diffusion limited. The membrane diffusion coefficient calculated from the graph was found to be 1.27 × 10⁻⁶ cm²/s and its theoretical value was 1.22 × 10⁻⁶ cm²/s. The stability of the carrier against leaching out of the membrane support as well as the integrity of membrane support was studied over a period of 30 days and was found to be satisfactory within the studied time period.     

Study of the Complexation,Adsorption and Electrode Reaction Mechanisms of Chromium(VI) and (III) with DTPA Under Adsorptive Stripping Voltammetric Conditions

The complexation of Cr(III) and Cr(VI) with diethylenetriaminepentaacetic acid (DTPA), the redox behavior of these complexes and their adsorption on the mercury electrode surface were investigated by a combination of electrochemical techniques and UV/vis spectroscopy. A homogenous two‐step reaction was observed when mixing Cr(III), present as hexaquo complex, with DTPA. The first reaction product, the electroactive 1 : 1 complex, turns into an electroinactive form in the second step. The results indicate that the second reaction product is presumably a 1 : 2 Cr(III)/DTPA complex. The electroreduction of the DTPA‐Cr(III) complex to Cr(II) was found to be diffusion rather than adsorption controlled.The Cr(III) ion, generated in‐situ from Cr(VI) at the mercury electrode at about ?50 mV (vs. Ag|AgCl) (3 mol L^?1 KCl), was found to form instantly an electroactive and adsorbable complex with DTPA. By means of electrocapillary measurements its surface activity was shown to be 30 times higher than that of the complex built by homogenous reaction of DTPA with the hydrated Cr(III). Both components, DTPA and the in‐situ built complex Cr(III) ion were found to adsorb on the mercury electrode.The effect of nitrate, used as catalytic oxidant in the voltammetric determination method, on the complexation reaction and on the adsorption processes was found to be negligible.The proposed complex structures and an overall reaction scheme are shown.     

Eu(III)在北山花岗岩上的吸附作用

用电位滴定法研究了甘肃北山花岗岩(BS03,600m)的酸、碱性质,用批式法研究了Eu(III)在该花岗岩上的吸附行为.实验结果表明:在离子强度I=0.1M的NaCl溶液中,北山花岗岩的pHPZNPC为9.4,当I增大至0.4M时,pHPZNPC为9.0.不同离子强度下花岗岩的电位滴定曲线与类似条件下蒙脱石的相仿.Eu(III)在北山花岗岩上的吸附分配比(Kd)随pH、离子强度和Eu(III)浓度的变化而变化.在低pH范围,Eu(III)的Kd值随离子强度的增大显著减小,而在高pH值范围,离子强度对Kd的影响甚微.用模型定量解释了Eu(III)在北山花岗岩上的吸附随pH、离子强度和Eu(III)浓度而变化的实验数据,该模型包含Eu3+与花岗岩发生的阳离子交换反应以及Eu(III)与花岗岩表面羟基发生两个内层表面配合反应(inner-sphere surface complexation reactions).用所建模型对离子强度为0.1M时Eu(III)在北山花岗岩上的吸附行为作了预测,并与文献报道的类似条件下Am(III)在北山花岗岩上的吸附实验数据作了比较.     

Complexes of Oxamic Acid with La(III), Gd(III), Tb(III), Er(III), Tm(III) and Lu(III)

The preparation, for the first time, of the deprotonated complexes of oxamic acid with La(III), Gd(III), Tb(III), Er(III), Tm(III) and Lu(III) is reported. Analytical results, conductometric measurements, magnetic moments and spectral data (IR and diffuse reflectance spectra) are discussed in terms of possible structural types. The oxamate anion acts as a N, O bidentate non-bridging ligand.     

Separation of Am(III), Cm(III) and Eu(III) by electro-spun polystyrene-immobilized CyMe4-BTPhen

The synthesis of a novel 5-(4-vinylphenyl)-CyMe₄-BTPhen actinide selective ligand using selenium free synthetic procedures is reported. For the first time, we report the electrospinning of this actinide selective ligand into a polystyrene fiber and investigate its selective removal of Am(III) from Eu(III) and Am(III) from Cm(III). At 4?M HNO₃, the resulting fibrous solid extractant produced separation factors of SF_Am/Eu?≈?57 and a small, but significant separation of SF_Am/Cm?≈?2.9.     

Crystal structure and fluorescence spectrum of the complex [Eu(III)(TTA)3(phen)]

The title complex Eu(III)(TTA)₃(phen) (where TTA = thenoyltrifluoroacetone monoanion; phen = 1,10-phenanthroline) has been synthesized in mixed solvents of acetone and ethanol (1:1 volume ratio) and its crystal structure has been determined by X-ray diffraction. The complex crystals are triclinic, space group P 1 (# 2) with cell dimensions of a = 1.32.41 (2) nm, b = 1.5278(4) nm, c = 0.9755(3) nm, α = 92.49 (2)°, β = 102.57(2)°, γ = 91.62(2)°, V = 1.9268(8) nm³, Z = 2, μ (Mo Ka)= 18.77 cm^?1, D_x=1.720 g/cm³. The coordination geometry of Eu atom is a distorted square antiprism, and the encapsulated structure that can meet the structural requirement of the typical europium luminescent sensor. The fluorescence spectrum suggests that the complex is a strong photoluminescent material.     

Kinetic Studies on the Complexation of Chromium(III) with some Amino Acids in Aqueous Acidic Medium

Summary.  The kinetics of the formation of the 1:3 complex of chromium(III) with L-glutamic acid and DL-lysine were studied spectrophotometrically at and 550 nm. The reaction was found to be first order in both reactants. Increasing the hydrogen ion concentration from 3.2×10⁻⁵ to 1.0×10⁻³ molċdm⁻³ retarded the reaction rate which is of the form . Values of 28.8 and 63.6 kJċmol⁻¹ were obtained for the energy of activation and −184 and −116 Jċ K⁻¹ċmol⁻¹ for the entropy of activation for L-glutamic acid and DL-lysine. The logarithms of the formation constants of the two complexes were found to be 5.9 and 5.1. Received January 7, 2000. Accepted (revised) March 8, 2000     

Thermogravimetric and spectroscopic studies on La(III) and Ce(III) complexes with some thio-schiff bases

Solid complexes of five derivatives of thio-Schiff bases with La(III) and Ce(III) ions were prepared and characterized by elemental and thermogravimetric analyses. The suggested general formula of the solid complexes is [ML₂(H₂O)X]·2H₂O, whereM=trivalent lanthanide ion,L=Schiff base andX=Cl^? or ClO ₄ ^? . Information about the water of hydration, the coordinated water molecules, the coordination chemistry and the thermal stability of these complexes was obtained and is discussed. Additionally, a general scheme of thermal decomposition of the lanthanide-Schiff base complexes is proposed.     

Synthesis and Spectroscopic Studies of Chosen Heteropolytungstates and Their Ln(III) Complexes

The heteropolytungstates [(Na)P₅W₃₀O₁₁₀]^4– (I), [(Na)Sb₉W₂₁O₈₆]^18– (II) and [(Na)As₄W₄₀O₁₄₀]^27– (III) and the monovacant Keggin structure of the general formula [XW_11–xMo_xO₃₉]^n– (X-Si, P; n = 7 for P and 8 for Si) (IV) as well as their europium(III) complexes were studied. The structures of I–IV as well as the europium(III) encrypted [(Eu)P₅W₃₀O₁₁₀]^12– (VI), [(Eu)Sb₉W₂₁O₈₆]^16– (VII), [(Eu)As₄W₄₀O₁₄₀]^25– (VIII) and sandwiched [Eu(XW_11–xMo_xO₃₉)₂]^n– (n =11 for P and n = 13 for Si) (V) complexes were synthesized and spectroscopically characterized. The complexes were studied using UV-Vis absorption and luminescence, as well as the laser-induced europium ion luminescence spectroscopy. Absorption spectra of Nd(III) were used to characterize the complexes formed. Excitation and emission spectra of Eu(III) were obtained for solid complexes and their solutions. The relative luminescence intensities of the Eu(III) ion, expressed as the ratio of the two strongest lines at 594 nm and 615 nm, = I₆₁₅/I₅₉₄, which is sensitive to the environment of the primary coordination sphere about the Eu(III) ion, was calculated. In the case of the sandwiched [Eu(XW_11–xMo_xO₃₉)₂]^n– complexes a linear dependence of the luminescence quantum yield of Eu(III) ion, , (calculated using [Ru(bpy)₃]Cl₂ as a standard) on the content of Mo (number of atoms, x) in the [Eu(XW_11–xMo_xO₃₉)₂]^n– structure was observed.     

Vibrational interactions in dimethylgold(III) halides and carboxylates

The far-infrared and Raman spectra of binuclear molecules [Me₂AuX]₂ (X = Cl, Br, I) and [Me₂Au(OOCR)]₂ (R = Me, CF₃, Bu^t, Ph) in the 600–70 cm⁻¹ region are reported. The experimentally measured vibrational frequencies of [Me₂AuX]₂ are in a good agreement with density functional theory predictions. The Au…Au vibrational interactions predicted to be in the 270–60 cm⁻¹ region of [Me₂AuX]₂ far-IR and Raman spectra have been observed. The Raman-active Au…Au vibrations of the [Me₂Au(OOCR)]₂ molecules were found to be in the same region as those of [Me₂AuX]₂. The Au–X stretching modes were observed between 100 and 250 cm⁻¹ in accordance with the DFT predictions. Their frequencies in the IR spectra of [Me₂AuX]₂ increase in the sequence I < Br < Cl while the AuC₂ stretching frequencies decrease in the same order. This fact might be an evidence of the decreasing covalent character of the gold-halogen bridges. The Au–O stretching bands of dimethylgold(III) carboxylates have been observed in the 500–250 cm⁻¹ region, and Au–C stretching frequencies of both [Me₂AuX]₂ and [Me₂Au(OOCR)]₂ compounds have been found between 600 and 500 cm⁻¹.