Investigation of Interaction of Lanthanides with Hemoglobin and Effect on Oxygen-Carrier Function

The preliminary studies of the effects of lanthanides(Lns) on hemoglobin are reported. It has been revealed that Ln ions reduce the oxygen saturation of hemoglobin and the oxygen-releasing potency of oxyhemoglobin under reduced partial pressure of oxygen. The Ln ions do not replace the iron atom in the heme probably due to the conformational change of hemoglobin induced by Ln binding, which was investigated by circular dichroism(CD) and fluorescence spectra.     

Studies on Heterobinuclear Complexes of Ln3 and Zn2 with Acyclic Polyether Schiff Base

Ｔｈｅｒａｐｉｄｌｙｇｒｏｗｉｎｇｉｎｔｅｒｅｓｔｉｎｐｏｌｙｎｕｃｌｅａｒｃｏｍｐｌｅｘｅｓａｒｉｓｅｓｆｒｏｍｔｈｅｓｉｇｎｉｆｉｃａｎｔｒｏｌｅｗｈｉｃｈｈａｓｐｌａｙｅｄｉｎｔｈｅｅｘｔｅｎｓｉｖｅａｒｅａｓｏｆｃａｔａｌｙｓｔｓ,ｍａｇｎｅ...     

Synthesis, Characterization and Fluorescence of Phenylcarboxymethyl Sulfoxide Complexes with Lanthanide Nitrates

Ｒａｒｅｅａｒｔｈｃｏｍｐｌｅｘｅｓｗｉｔｈｓｕｌｆｏｘｉｄｅａｎｄａｒｏｍａｔｉｃｃａｒｂｏｘｙｌａｃｉｄｈａｖｅｂｅｅｎｗｉｄｅｌｙｓｔｕｄ ｉｅｄ[1～ 3 ] .Ｉｔｉｓｐｒｏｖｅｄｔｈａｔｔｈｅｙｂｏｔｈｈａｖｅｂｅｔ ｔｅｒｆｌｕｏｒｅｓｃｅｎｃｅｃｈａｒａｃｔｅｒ .Ｈｏｗｅｖｅｒｔｈｅａｒｏ ｍａｔｉｃｃａｒｂｏｘｙｌｏｆｒａｒｅｅａｒｔｈｃｏｍｐｌｅｘｅｓｈａｖｅｖｅｒｙｈｉｇｈｆｌｕｏｒｅｓｃｅｎｃｅｅｍｉｓｓｉｏｎｉｎｔｅｎｓｉｔｙａｎｄｓｔａｂｉｌｉｔｙ ,ｂｕｔｓｏｌｕｂｉｌｉｔｙｉ…     

Low Temperature Preparation of Ceria Solid Solutions Doubly Doped with Rare-Earth and Alkali-Earth and Their Properties as Solid Oxide Fuel Cells

Solidoxidefuelcells (SOFCs)haveseveraldis tinctadvantages ,e .g .,highenergyconversioneffi ciency ,wideadaptabilitytofuels ,theusageofnon preciousmaterials ,noliquids ,nocorrosions ,modularconstructionandmuchlowerproductionofNOx,SOxandnoise .Therefore ,theyreceiveincreasingatten tion[1,2 ] .AtypicalSOFCwhichutilizesyttria stabi lizedzirconia (YSZ)astheelectrolyterequireshighoperationtemperaturesuchas 10 0 0℃togainhighe noughionicconductivity .Loweringtheoperationtem peratureto 80 0℃wou…     

Hydrothermal Synthesis of RbLn2F7 and VUV Spectroscopy of RbLn2 F7 ：Eu^3＋（Ln=Gd, Y）

RbLn2F7（Ln = Gd, Y, Er, Yb and Lu）, crystallized in the hexagonal RbEr2F7 structure type, is synthesized by a hydrothermal method. The excitation spectra of Eu^3 ＋ -doped RbGd （Y）2F7 suggest that the oxygen content is very low in the samples obtained by hydrothermal synthesis. Only the f-f transitions of Gd^3＋ ions are observed in the excitation spectrum of RbGd2F7：Eu^3＋ （0.5mol%）, while those of Eu^3＋ ions do not appear. When the Gd^3＋ ions are excited, the absorbed energy is transferred efficiently from Gd^3＋ to Eu^3＋ . The spectra show that the doped Eu^3＋ ions are located in non-centrosymmetric sites in hexagonal RbLn2F7.     

Theoretical elucidation of rare earth extraction and separation by diglycolamides from crystal structures and DFT simulations

Diglycolamides(DGAs) show excellent application prospects for the extraction and separation of rare earth metals from highly radioactive liquid wastes and rare earth ores.The extraction ability of DGAs for rare earth ions in nitrate or chloride media increases with increasing atomic number of the rare earth metal.To understand the origin of this phenomenon,three binuclear crystals [Ln(TEDGA)3][Ln(NO_3)_6] of N,N,N',N'-tetraethyldiglycolamide(TEDGA) with rare earth ions La(Ⅲ),Pr(Ⅲ) and Eu(III) were prepared and characterized crystallographically.The three complexes belong to the triclinic crystal system,P-1 space group.The bond lengths of Ln-O_(amide) are significantly shorter than those of Ln-O_(ether) in the same crystal.The Ln-O_(amide) and Ln-O_(enher) bond lengths gradually decrease with increasing atomic number of the rare earth ion.The dihedral angle formed by TEDGA and metal ions through the tridentate coordination gradually increases with increasing metal ion atomic number,tending toward the formation of sizeable planar coordination structures for the most massive rare earth ions.The structures of the compounds formed by the extractant and metal ion were optimized by means of DFT simulations.We find that the interaction between TEDGA and the rare earth ion is dominated by electrostatic interaction by analyzing binding energy,WBIs,Mulliken charge,natural electron configurations,and molecular orbital interaction.The covalent component of the Ln-O bonds of the complexes increases with increasing metal atomic number.The observed increase in extraction and separation capacity of diglycolamides for rare earth ions with increasing atomic number might be due to the formation of two fivemember rings by one tridentate ligand.The rare earth ions with large atomic numbers tend to form planar structures with large dihedral angles with DGA ligands.     

Synthesis and spectral characteristics of La2MoO6：Ln3＋ （Ln=Eu, Sm, Dy, Pr, Tb） polycrystals

The novel phosphors of La 2 MoO 6 activated with the trivalent rare earth Ln 3+ (Ln=Eu, Sm, Dy, Pr, Tb) ions were synthesized by solid state reactions at high temperature in air atmosphere, and their phase impurities and luminescent properties were studied. The photoluminescence (PL) excitation and emission spectra, and decay curves were employed to study their luminescence properties. The lifetimes of the characteristic emissions from Ln 3+ ions were in the order of millisecond except Pr 3+ ions. (LaEu 1-x ) 2 MoO 6 was a promising phosphor for practical application and the optimum concentration was x=0.075. The concentration quenching mechanism of Eu 3+ was also discussed by theoretical fitting using Burshtein model.     

Studies on some lanthanide（Ⅲ） complexes with 4-hydroxyantipyrine

Seven new lanthanide（Ⅲ） complexes with 4-hydroxyantipyrine were synthesized. These complexes were characterized by elemental analysis, molar conductance, magnetic moment measurements, FT-IR, electronic and 1HNMR spectra, X-ray powder diffraction, and thermogravimetric studies. The ligand, 4-hydroxyantipyrine （hap）, contained carbonyl oxygen and hydroxyl oxygen as potential donor sites. On coordination, deprotonation occurred and as a result, hap acted as a monobasic bidentate ligand. A coordination number 6 was assigned to the lanthanide（Ⅲ） ions in these complexes with orthorhombic structure. All the complexes were thermally stable-150℃ and underwent decomposition in three stages with the formation of Ln2O3 as the final residues.     

Hydrothermal syntheses and characterization of three lanthanide coordination complexes constructed by 2,2’:6’,2’’-terpyridine and 2,2’-biphenyldicarboxylic acid

Two 1D coordination polymers [Ln2(dpdc)3(tpy)2·H2O]n [Ln=Nd 1, Yb 2, H2dpdc=2,2’-biphenyldicarboxylic acid and tpy= 2,2’:6’,2’’-terpyridine] and one dinuclear complex Er2(dpdc)2(Hdpdc)2(tpy)2 3 were obtained via hydrothermal reactions and determined by X-ray diffraction analysis. The crystal structure data of 1 and 2 revealed that two coordination polymers were isostructural and possessed a 1D chain framework consisting of eight-coordinated Ln(III) centers. In the asymmetric unit, the two Er(III) ions in 3 were both nine-coordinated and had similar coordination environments. The Er(III) ions were bridged by dpdc2-ligands into dinuclear structures. The complexes were also characterized by IR spectra and thermogravimetric analysis. The solid fluorescence of 1 and 3 was also investigated at room temperature.     

Synthesis and Characterization of Some Lanthanide（Ⅲ） Complexes with 4- [N-（2-methoxy benzylinine）formy1]-2, 3-dimethyl-1-phenyl-3-pyazolin-5-one

A series of seven novel lanthanide（Ⅲ ） nitrato complexes with 4-[ N-（2-methoxybenzylimine）formyl] 1-2, 3- dimethyl-1-phenyl-3-pyazolin-5-one （2mbfa）, were synthesized. These complexes were characterized by elemental analysis, molecular mass determination, conductance and magnetic moment measurements, IR, UV-visible, and ^13CNMR spectral studies, In these complexes, the Schiff base, 2mbfa, acts as neutral bidentate ligand by utilizing the carbonyl oxygen and azomethine nitrogen as donor sites. All the three nitrate ions are also coordinated unidentately with 7 coordination for the lanthanide（Ⅲ） ions with a tentative monocapped octahedral geometry for the complexes. All the seven lanthanide（Ⅲ） complexes have a general formula, [ Ln（2mbfa）：（NO3）3 ].     

Synthesis and Characterization of Rare Earth Complexes of Ferrocenylcarbonylhydrazine

Ｔｈｅｍｅｔａｌｃｏｍｐｌｅｘｅｓｏｆｈｙｄｒａｚｉｄｅｓｈａｖｅａｔｔｒａｃｔｅｄｃｏｎｓｉｄｅｒａｂｌｅｉｎｔｅｒｅｓｔｏｗｉｎｇｔｏｔｈｅｉｒａｎｔｉｆｕｎｇａｌａｎｄａｎｔｉｂａｃｔｅｒｉａｌａｃｔｉｖｉｔｉｅｓ[1 ,2 ] .Ｔｈｅｙｃａｎａｌｓｏｂｅｕｓｅｄａｓａｎａｌｙｔｉｃａｌｒｅａｇｅｎｔｓ[3 ]ａｎｄｅｘｔｒａｃｔｉｎｇａｇｅｎｔｓｆｏｒｍｅｔａｌｓａｌｔｓ[4 ] .Ｍａｎｙｃｏｍｐｌｅｘｅｓｏｆｈｙｄｒａｚｉｄｅｓｈａｖｅｂｅｅｎｓｙｎｔｈｅｓｉｚｅｄａｎｄｃｈａｒａｃｔｅｒｉｚｅｄ[5]…     

Organolanthanide Compounds Containing Methanesulfonate and Pyrazinamide Ligand in Styrene Polymerization

The synthesis of organolanthanide compounds identified as LnCp*(MS)2PzA, Ln=Sm, Tb, Yb (MS=methanesulfonate, Cp*=pentamethylcyclopentadienyl, and PzA=pyrazinamide), by the reaction of coordination compounds Ln(MS)3(PzA)4 with NaCp in THF was reported. The complexes were formulated according to elemental analyses, complexometric titration with EDTA (%Ln), and 1H NMR. IR spectroscopy revealed that PzA coordinates with lanthanide(Ⅲ) ions and methanesulfonate coordinates via oxygen atoms in a non-equivalent manner. In preliminary catalytic studies, these compounds were active in styrene polymerization that used MAO as a cocatalyst with an activity of 12.3 kg PS mol Sm-1h-1. Differential scanning calorimetry (DSC) of polystyrene showed that the polymer was mainly atactic.     

Synthesis, Crystal Structure of [ （MeC5H4）2Ln（μ-OCH2 CH2NMe2 ） ]2 （Ln = Sm, Y, Nd） and Their Catalytic Activity for Ring-Opening Polymerization of ε-Caprolactone

Reaction of (MeC5H4)3Ln with HOCH2CH2NMe2 in tetrahydrofuran (THF) gives the new complexes [ (MeC5H4)2Ln(μ-OCH2CH2NMe2)]2(Ln = Sm, Y, Nd) with nitrogen functionalized μ-alkoxide ligand. The complexes were characterized by elemental analysis and IR, and [ (MeC5H4)2Sm(μ-OCH2CH2NMe2)]2 was structurally characterized by the X-ray diffraction to be a dimer formed by two unsymmetric oxygen bridges. The complex has a tricyclic skeleton with the additional two Sm- N bonds via intmmoleeular coordination of OCH2CH2NMe2. The coordination number of the central metal Sm is nine. The tide complexes show good catalytic activity for ring-opening polymerization of ε-capmlactone.     

Syntheses, characterization, and luminescence of two lanthanide complexes [Ln2(acetate)6(H2O)4]·4H2O (Ln=Tb(1), Sm(2))

Two dinuclear compounds [Ln2(acetate)6(H2O)4]·4H2O (Ln=Tb(1), Sm(2)) were obtained by the hydrothermal reaction of Ln2O3 with malonic acid at 150 ℃. Both compounds were characterized by elemental analyses, infrared spectra, and single crystal X-ray diffraction. The results showed that complexes 1 and 2 were isomorphous and crystallize in triclinic space group P(-1). The coordination geometry around Ln(III) ions in the complexes 1 and 2 was a distorted tricapped trigonal prism with a nine coordination. In the crystal, the molecular organization was further stabilized by well-defined weak hydrogen bonding interactions between the neutral dinuclear molecular units that led to the formation of a three-dimensional network. The fluorescence properties of the two complexes 1 and 2 in organic solvents were also studied. The results show that the ligand acetate favored energy transfer to the emitting energy level of Tb(III) in complex 1. Some factors that influence the fluorescent intensity were also discussed in the article.     

Electroanalytical tools to investigate the divalent state of Eu（III） and Nd（III） ions in non-aqueous medium

The divalent state of Ln(Ⅲ) ions has attracted much interest because of their ability to serve isomorphously in many biological sys-tem of divalent Ca(II) ion. Therefore, present paper deals with the study of divalent state of Eu(Ⅲ) and Nd(Ⅲ) ions in non-aqueous medium. In present study, cyclic voltammetry and chronopotentiometry were utilized to establish the divalent state of Eu(Ⅲ) and Nd(Ⅲ) ions. The cy-clic voltammetric technique showed two-step reduction process at cathode for both Ln(Ⅲ) ions under specified experimental conditions and chronopotentiometric method also showed two different transition times (). Looking to the shape of cyclic voltammogram we calculated het-erogeneous forward rate constant (K0fh, cm/s) and diffusion coefficient (D, cm2/s) for both ions, which suggested that sweep rate had great ef-fect on the shape of cyclic voltammogram of Eu(Ⅲ) and Nd(Ⅲ) ions. The result of chronopotentiometry also suggested that stable divalent states of Eu(Ⅲ) and Nd(III) ions existed with chronopotentiogram with two distinct transition times. The diffusion coefficients (D, cm2/s) were calculated from Sand equation. The diffusion coefficients of both techniques were compared and the results suggested that the system at electrode surface was changing from being reversible to irreversible.     

Photoluminescence properties of dinuclear lanthanide complexes in visible and near-infrared region

Several dinuclear lanthanide complexes of Ln2(HTH)6TPPHZ (Ln=Eu, Sm, Er, Nd, Yb, Ho; TPPHZ=Tetrapyrido (3,2-a:2',3'-c:3',2"-h:2"',3'"-j) phenazine; HTH=4,5,5,6,6,6-heptafluroro-1-(2-thienyl)hexane-1,3-dione were synthesized and their photoluminescence properties were investigated. After ligand-mediated excitation, all the complexes showed the characteristic luminescence of the corresponding Ln(III) ions in the visible and NIR regions attributed to energy transfer from the ligands to the metal center. For Eu...     

Phase Behavior of Rare Earth Manganites

Among complex oxides containing rare earth and manganese BaLn2Mn2O7(Ln=rare earth) with the layered perovskite type and Ln2(Mn,M)O7 with pyrochlore-related structure were studied since these compounds show many kinds of phases and unique phase transitions. In BaLn2Mn2O7 there appear many phases, depending on the synthetic conditions for each rare earth. The tetragonal phase of so-called Ruddlesden-Popper type is the fundamental structure and many kinds of deformed modification of this structure are obtained. For BaEuzMn207 at least five phases have been identified from the re-sults of X-ray diffraction analysis with the space group P42/mnm, Fmmm, Immm and A2/m in addition to the fundamental tetragonal 14/mmm phase. In the pyrochlore-related type compounds, LnzMn2-xMxO7(M=Ta,Nb,W etc),there also appear several phases with different crystal structures. With regard to every rare earth, Ln2MnTaO7 phase is stable only for excess Ta and can be obtained under high oxygen partial pressure process. This group has trigonal structure with zirkelite type (P3121 space group). On the other hand Ln2Mn2/3Nb4/307 phase has monoclinic (C2/c space group)and zireonolite type structure. All of these structural models have the fundamental structure based on HTB (hexagonal tungsten bronze) layers formed by the arrangement of oxygen octahedra.     

Physico-chemical properties of 3-methoxy-2-nitrobenzoates of some rare earth elements（Ⅲ）

The complexes of 3-methoxy-2-nitrobenzoates of Pr(III), Nd(III), Sm(III), Eu(III), Gd(III), Tb(III), Er(III) and Tm(III) with the formula: Ln(C8H6NO5)3·2H2O, where Ln=lanthanides(III), were synthesized and characterized by elemental analysis, Forier transform irtrared (FTIR) spectroscopy, magnetic and thermogravimetric studies and also by X-ray diffraction (XRD) measurements. The complexes had col- ours typical for Ln(III) ions. The carboxylate groups bound as bidentate chelating. On heating to 1173 K in air they decomposed in the same way, at first, dehydrated in one step to anhydrous salts, and then decomposed to the oxides of respective metals with intermediate formation of the oxycarbonates. The enthalpy values of the dehydration process changed from 133.72 to 44.50 kJ/mol. Their solubility in water at 293 K was of the order of 10-4 mol/dm3. The magnetic moments of analysed complexes were determined by Gouy’s method in the range of 76-303 K.     

Syntheses and Characterizations of Cu-Ln Heterobinuclear Complexes with Schiff Base from 3-Formylsalicylic Acid and Ethylene Diamine

ＴｈｅｈｏｍｏａｎｄｈｅｔｅｒｏｂｉｎｕｃｌｅａｒｃｏｍｐｌｅｘｅｓｏｆｔｈｅｄｂｌｏｃｋｅｌｅｍｅｎｔｓｃｏｏｒｄｉｎａｔｅｄｗｉｔｈＥＳｈａｖｅｂｅｅｎｓｔｕｄｉｅｄ[1,2].Ｈｏｗｅｖｅｒ,ｌａｎｔｈａｎｉｄｅｈｅｔｅｒｏｂｉｎｕｃｌｅａｒｃｏｍｐｌｅｘｅｓｗｉｔｈｔｈｉｓｌｉｇａｎｄｈａｖｅｒａｒｅｌｙｂｅｅｎｒｅｐｏｒｔｅｄ.ＵｓｉｎｇＮａ2ＣｕＥＳ·Ｈ2Ｏａｓｌｉｇａｎｄ,ｗｅｓｙｎｔｈｅｓｉｚｅｄｓｅｖｅｎｈｅｔｅｒｏｂｉｎｕｃｌｅａｒｃｏｍｐｌｅｘＣｕＬｎＥＳＣｌ·ｎＨ2Ｏ(Ｆｉｇ.1,Ｌｎ=…     

Crystal Structure and Luminescence Property of Lanthanide Complexes with 2-Fluorobenzoic Acid and 2,2''-Bipyridine

The two compounds of [Ln(2-FBA)3·2,2'-bpy]2 (2-FBA=2-fluorobenzoato, 2,2'-bpy=2,2'-bipyridine, Ln=Eu(1), Dy(2)) were synthesized and their structures were determined by X-ray diffraction method. Crystallized complexes 1 and 2 are isomorphous, monoclinic system with P21/n space group. The two complexes are binuclear molecule with an inversion center. The two lanthanide ions are linked by four bridged 2-FBA ligands and each lanthanide ion is further bonded to one chelated bidentate 2-FBA ligand and one 2,2'-bipyridine molecule. The coordination number of metal ion is eight. The europium complex exhibits strong red fluorescence. 5D0→7Fj (j= 1～4) transition emission of Eu3 ion was observed.