- Synthesis and characterization of pentaphenyldiytterbium Ph2Yb(THF)(μ-Ph)3Yb(THF)3
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The binuclear ytterbium complex Ph2Yb(THF)(μ-Ph)3Yb(THF)3 (1) was obtained in reactions of naphthaleneytterbium C10H8Yb(THF)2 with diphenylmercury or triphenylbismuth in THF.An X-ray crystallographic study (a = 11.099(2), b = 19.876(4), c = 19.723(4) Angstroem, β = 103.33(3) deg, Z = 2, space group P21) showed that the molecule of 1 has two Yb atoms coupled by three bridging Ph groups, which are linked with the first Yb atom by an η1 bond and with the second one by an unsymmetrical η2 bond.In addition the first Yb atom has an η1 bond with two terminal Ph groups and one coordinated THF molecule whereas the second Yb atom is linked with three THF molecules.The coordination of both Yb atoms is a distorted octahedron.In the crystal, there are two symmetrically independent molecules of 1 with a similar structure.The Yb-C (terminal Ph) bond length is 2.388-2.463 Angstroem.The η1- and η2-Yb-C (bridging Ph) bond distance varies in the ranges 2.475-2.584, 2.547-2.751 and 2.877-3.250 Angstroem.The magnetic moment μeff(per YbIII atom) is 4.0 +/- 0.05 μB.Reactions of 1 with water, HCl, Br2, MeI and CO2 give benzene, bromobenzene, toluene and PhCOOH, respectively.
- Bochkarev, Mikhail N.,Khramenkov, Vladimir V.,Rad'kov, Yury F.,Zakharov, Lev N.,Struchkov, Yury T.
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- Scintillators based on ytterbium chloride adducts with neutral organophosphorus extractants for detecting solar neutrino for LENS (Low-Energy Neutrino Spectroscopy) experiment
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The main features of extraction of ytterbium chloride with dibutyl butylphosphonate (DBBP) and triisoamylphosphine oxide (TIAPO) were studied. The effects of temperature, DBBP and TIAPO concentrations in 1,2,4-trimethylbenzene (TMB), and concentrations of
- Danilov,Krylov,Korpusov,Kostikova,Barabanov,Bezrukov,Kornoukhov,Nesterova,Yanovich,Yakshin,Tsarenko,Cattadori,Ferrari,Falgiani
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- IR luminescence of neodymium(III) and ytterbium(III) ions in complexes with N-alkyl-substituted 2-aminobenzoic acids
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The luminescence of neodymium(III) and ytterbium(III) ions in complexes with N-alkyl-substituted 2-aminobenzoic acids has been studied. The luminescence spectra of the Nd(III) complexes show two bands with maxima at 875 and 904 and 1060 nm, and the spectra of the Yb(III) complexes show one band at 980 nm. The introduction of an additional ligand or some surfactants into the Nd(III) and Yb(III) coordination sphere leads to an increase in the luminescence intensity. A correlation between the luminescence intensity of Nd(III) and Yb(III) 2(N-alkylamino)benzoates and the length of the hydrocarbon radical bound to the nitrogen atom has been studied.
- Meshkova,Topilova,Devyatykh,Gusev,Shul'Gin
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- Preparation of organoytterbium reagent from ytterbium trichloride and organomagnesium
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The preparation of organolanthanoid species from diorganomagnesium and lanthanoid salt is discussed. Treatment of cerium trichloride or ytterbium trichloride with diorganomagnesium gave the corresponding organolanthanoid species much more efficiently than treatment of the salt with organomagnesium halide.
- Matsubara, Seijiro,Ikeda, Takanori,Oshima, Koichiro,Utimoto, Kiitiro
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- Water-soluble Yb3+, Tm3+ codoped NaYF4 nanoparticles: Synthesis, characteristics and bioimaging
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Water soluble NaYF4 nanocrystals codoped with 20 mol% Yb 3+, 0.5 mol% Tm3+ were prepared by a facile solvothermal approach using polyvinylpyrrolidone (PVP) as a surfactant. The upconversion NaYF4 nanocrystals were pure cubic phase with an average size of ~40 nm. They could be well redispersed in water to form a clearly transparent solution without obvious precipitation. With the excitation of a 980-nm diode laser, the nanocrystal solution presents bright violet and blue upconversion luminescence. These upconversion nanoparticles (UCNPs) were incubated with HeLa cells at 37 °C for 24 h, and bright blue upconversion luminescence were observed from the UCNPs endocytosed into the HeLa cells on a microscope equipped with a 980-nm fiber laser. These results indicated that the UCNPs had potential applications for biological imaging as luminescent probes.
- Chen, Huan,Zhai, Xuesong,Li, Duo,Wang, Lili,Zhao, Dan,Qin, Weiping
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- Redox reaction Yb(III) + e = Yb(II) in a molten eutectic mixture NaCl-2CsCl
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Potentiometric method was used to measure the redox potentials of Yb 3+/Yb2+ in a eutectic melt of sodium and cesium chlorides relative to a chlorine reference electrode in the temperature range 823-973 K. The basic thermodynamic cha
- Novoselova,Smolenskii
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- Accessing decaphenylmetallocenes of ytterbium, calcium, and barium by desolvation of solvent-separated ion pairs: Overcoming adverse solubility properties
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The redox-transmetalation ligand-exchange reaction of ytterbium or calcium metal with 2 equiv of pentaphenylcyclopentadiene (C5Ph5H) and 1 equiv of HgPh2 in thf afforded the solvent-separated ion pairs (SSIPs) [M(thf)
- Deacon, Glen B.,Forsyth, Craig M.,Jaroschik, Florian,Junk, Peter C.,Kay, Danielle L.,Maschmeyer, Thomas,Masters, Anthony F.,Wang, Jun,Field, Leslie D.
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- X-RAY POWDER DIFFRACTION STUDY OF THE YbCl2-Ybl2 SYSTEM.
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The YbCl//2-Ybl//2 system has been investigated over the entire composition range by examining at room temperature both slowly cooled and quenched fused samples of the reactants. The system may be described in terms of mole% Ybl//2, Y, as follows: for Y equals approximately 85 to 100, a YbI//2 (CdI//2-type) solid solution region prevails; for Y equals approximately 55 to approximately 85, 'YbCl//0//. //3I//1//. //7,' YbCl//2, and 6R- 'YbCl//0//. //5I//1//. //5' are found; for Y equals 10 to approximately 55, the YbCl//2 and 6R- 'YbCl//0//. //5I//1//. //5' phases coexist; and for Y equals 0 to 10, a YbCl//2 solid solution region is found. The unusual behavior of the system is discussed and compared with that of related systems.
- Lasocha,Voos-Esquivel,Hodorowicz,Kim,Eick
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- Lanthanide carbonates
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The crystal and molecular structures of the rare earth carbonates with the general formulae [C(NH2)]3 [Ln(CO3)4 (H2O)]·2H2O (where Ln = Pr3+,Nd 3+,Sm3+,Eu3+,Gd3+,Tb 3+)and [C(NH2)]3 [Ln(CO3) 4]·2H2O (where Ln = Y3+,Dy 3+,Ho3+,Er3+, Tm3+,Yb 3+,Lu3+) were determined. The crystals consist of monomeric [Ln(CO3)4 (H2O)] 5-or [Ln(CO3)4] 5-complex anions in which the carbonate ligands coordinate to the Ln3+ion in a bidentate manner. The spectroscopic (UV/Vis/NIR and IR) properties of the crystalline lanthanide carbonates, as well as their aqueous solutions, were determined. Correlation between the spectroscopic and the structural data enabled us to conclude that the [Ln(CO3)4 (OH)]6-and [Ln-(CO 3)4]5- species predominate in the light and heavy lanthanide solutions, respectively. The nature of the Ln-O interaction was also discussed. The experimental data, as well as the theoretical calculations, indicated that the Ln-O(CO3 2-) bond is more covalent than the Ln-O(OH2) bond. Moreover, the covalency degree is larger for the heavy lanthanide ions. Inspection of the NBO results revealed that the oxygen hybrids, with the approximate composition sp4, form strongly polarized bonds with the 6s6p5d4 hybrids of lutetium. 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
- Janicki, Rafal,Starynowicz, Przemyslaw,Mondry, Anna
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p. 3601 - 3616
(2011/10/11)
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- Synthesis, characterization and thermal behaviour of solid-state tartrates of heavy trivalent lanthanides and yttrium(III)
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Solid state Ln2-L3 compounds, where Ln stands for heavy trivalent lanthanides (terbium to lutetium) and yttrium, and L is tartrate [(C4H4O6)-2] have been synthesized. Simultaneous thermogra
- Ambrozini, B.,Dametto, P. R.,Ionashiro, M.
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p. 867 - 871
(2011/10/31)
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- Analysis of the conformational behavior and stability of the SAP and TSAP isomers of lanthanide(III) NB-DOTA-type chelates
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Controlling the water exchange kinetics of macrocyclic Gd3+ chelates, a key parameter in the design of improved magnetic resonance imaging (MRI) contrast media, may be facilitated by selecting the coordination geometry of the chelate. The water exchange kinetics of the mono- capped twisted square antiprism (TSAP) being much closer to optimal than those of the mono capped square antiprism (SAP) render the TSAP isomer more desirable for high relaxivity applications. Two systems have been developed that allow for selection of the TSAP coordination geometry in 1,4,7,10-tetraazacyclododecane-1,4,7,10- tetraacetic acid (DOTA)-type Gd3+ chelates, both based upon the macrocycle nitrobenzyl cyclen. In this paper we report investigations into the stability and formation of these chelates. Particular focus is given to the production of two regioisomeric chelates during the chelation reaction. These regioisomers are distinguished by having the nitrobenzyl substituent either on a corner or on the side of the macrocyclic ring. The origin of these two regioisomers appears to stem from a conformation of the ligand in solution in which it is hypothesized that pendant arms lie both above and below the plane of the macrocycle. The conformational changes that then result during the formation of the intermediate H2GdL+ chelate give rise to differing positions of the nitrobenzyl substituent depending upon from which face of the macrocycle the Ln3+ approaches the ligand.
- Tircso, Gyula,Webber, Benjamin C.,Kucera, Benjamin E.,Young, Victor G.,Woods, Mark
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p. 7966 - 7979
(2011/10/09)
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- IR luminescence of neodymium(III) and ytterbium(III) complexes with acylpyrazolones in solutions
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Acylpyrazolones (L1-L5) have been synthesized and the conditions of their complexation with neodymium(III) and ytterbium(III) ions in aqueous solutions have been elucidated. The component ratio in the synthesized complexes is Nd(Yb) : L = 1 : 1. The conditions of excitation and luminescence of the ligands and complexes have been studied. The formation of mixed-ligand complexes upon the introduction of trio-ctyl- or triphenylphosphine oxide leads to a considerable rise of neodymium and ytterbium. In the presence of 1,10-phenanthroline and bathophenanthroline, competing complexation leads to a 20-70% decrease in luminescence intensity. The introduction of water-miscible organic solvents (30 vol %) decreases the Nd(III) and Yb(III) luminescence intensity by a factor of 9-20. Pleiades Publishing, Ltd., 2011.
- Meshkova,Matiichuk,Potopnyk,Topilova,Gorodnyuk,Olenich,Bol'Bot
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p. 899 - 905
(2012/03/12)
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- Comparison of covalency in the lanthanide chloride and nitrate complexes based on the adsorption data on zeolite y
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The changes of the distribution constants Kd of lanthanide chlorides in the system: zeolite Y (solid phase)-sodium chloride (aqueous phase) were investigated. The evident tetrad effect in the change of log Kd values within the lantha
- G?adysz-P?aska, Agnieszka,Majdan, Marek,Ferenc, Wies?awa,Sarzyński, Jan
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p. 469 - 474
(2012/03/22)
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- Luminescent properties of ytterbium-doped ternary lanthanum chloride
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Studies of the absorption and temperature dependence of photoluminescence spectra and luminescence decay times of the intra-shell f-f transitions ( 2F5/2 ? 2F7/2) of Yb 3+ ions in K2LaClsu
- Kaminska,Cybińska,Zhydachevskii,Sybilski,Meyer,Suchocki
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p. 7993 - 7997
(2011/08/03)
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- Synthesis, characterization and thermal behaviour of heavy lanthanide and yttrium pyruvates in the solid state
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Solid-state Ln-L compounds, where Ln stands for heavy trivalent lanthanides or yttrium (III) (Tb-Lu, Y) and where L is pyruvate, have been synthesized. Thermogravimetry and derivative thermogravimetry (TG/DTG), differential scanning calorimetry (DSC), X-R
- Siqueira,De Carvalho,Rodrigues,Ionashiro,Bannach,Ionashiro
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- Synthesis, characterization and thermal behaviour of solid-state 3-methoxybenzoates of heavy trivalent lanthanides and yttrium(III)
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Solid-state Ln(L)3 compounds, where Ln stands for trivalent Tb, Dy, Ho, Er, Tm, Yb, Lu and Y, and L is 3-methoxybenzoate, have been synthesized. X-ray powder diffractometry, infrared spectroscopy, complexometry and elemental analysis were used to characterize the compounds. Inorder to study the thermal behaviour of these compounds simultaneous th ermogravimetry and differential thermal analysis (TG-DTA) and differential scanning calorimetry (DSC) were used. The results provided information on the composition, dehydration, polymorphic transformation, thermal stability and thermal decomposition of the synthesized compounds.
- Dametto, P. R.,Ambrozini, B.,Siqueira, A. B.,Carvalho, C. T.,Ionashiro, M.
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p. 933 - 940
(2011/01/06)
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- Structural characterization of methanol substituted lanthanum halides
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The first study into the alcohol solvation of lanthanum halide [LaX3] derivatives as a means to lower the processing temperature for the production of the LaBr3 scintillators was undertaken using methanol (MeOH). Initially the de-hydration of {[La(μ-Br)(H2O)7](Br)2}2 (1) was investigated through the simple room temperature dissolution of 1 in MeOH. The mixed solvate monomeric [La(H2O)7(MeOH)2](Br)3 (2) compound was isolated where the La metal center retains its original 9-coordination through the binding of two additional MeOH solvents but necessitates the transfer of the innersphere Br to the outersphere. In an attempt to in situ dry the reaction mixture of 1 in MeOH over CaH2, crystals of [Ca(MeOH)6](Br)2 (3) were isolated. Compound 1 dissolved in MeOH at reflux temperatures led to the isolation of an unusual arrangement identified as the salt derivative {[LaBr2.75·5.25(MeOH)]+0.25 [LaBr3.25·4.75(MeOH)]-0.25} (4). The fully substituted species was ultimately isolated through the dissolution of dried LaBr3 in MeOH forming the 8-coordinated [LaBr3(MeOH)5] (5) complex. It was determined that the concentration of the crystallization solution directed the structure isolated (4 concentrated; 5 dilute) The other LaX3 derivatives were isolated as [(MeOH)4(Cl)2La(μ-Cl)]2 (6) and [La(MeOH)9](I)3·MeOH (7). Beryllium Dome XRD analysis indicated that the bulk material for 5 appear to have multiple solvated species, 6 is consistent with the single crystal, and 7 was too broad to elucidate structural aspects. Multinuclear NMR (139La) indicated that these compounds do not retain their structure in MeOD. TGA/DTA data revealed that the de-solvation temperatures of the MeOH derivatives 4-6 were slightly higher in comparison to their hydrated counterparts.
- Boyle, Timothy J.,Ottley, Leigh Anna M.,Alam, Todd M.,Rodriguez, Mark A.,Yang, Pin,Mcintyre, Sarah K.
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p. 1784 - 1795
(2010/07/03)
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- Near-infrared luminescent xerogel materials covalently bonded with ternary lanthanide [Er(III), Nd(III), Yb(III), Sm(III)] complexes
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A β-diketone ligand 4,4,5,5,5-pentafluoro-1-(2-naphthyl)-1,3- butanedione (Hpfnp), which contains a pentafluoroalkyl chain, was synthesized as the main sensitizer for synthesizing new near-infrared (NIR) luminescent Ln(pfnp)3phen (phen = 1,10-p
- Feng, Jing,Yu, Jiang-Bo,Song, Shu-Yan,Sun, Li-Ning,Fan, Wei-Qiang,Guo, Xian-Min,Dang, Song,Zhang, Hong-Jie
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p. 2406 - 2414
(2009/06/28)
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- Stability, water exchange, and anion binding studies on lanthanide(III) complexes with a macrocyclic ligand based on 1.7-diaza-12-crown-4: Extremely fast water exchange on the Gd3+ complex
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The picolinate-derivative ligand based on the 1,7-diaza-12-crown-4 platform (bp12c4 2-) forms stable Ln3+ complexes with stability constants increasing from the early to the middle lanthanides, then being relatively constant for the
- Palinkas, Zoltan,Roca-Sabio, Adrian,Mato-lglesias, Marta,Esteban-Gomez, David,Platas-Iglesias, Carlos,De Blas, Andres,Rodriguez-Blas, Teresa,Toth, Eva
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p. 8878 - 8889
(2009/12/25)
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- Comparison of thermal properties of lanthanide trimellitates prepared by different methods
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By diffusion in gel medium new complexes of formulae: Nd(btc) ·6H2O, Gd(btc)·4.5H2O and Er(btc)?5H2O (where btc=(C6H3(COO)33-) were obtained. Isomorphous compounds were crystallized in the
- Lyszczek, Renata
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p. 833 - 838
(2009/02/07)
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- Versatile synthesis strategy for carboxylic acid-functionalized upconverting nanophosphors as biological labels
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Up-converting rare-earth nanophosphors (UCNPs) have great potential to revolutionize biological luminescent labels, but their use has been limited by difficulties in obtaining UCNPs that are biocompatible. To address this problem, we have developed a simple and versatile strategy for converting hydrophobic UCNPs into water-soluble and carboxylic acid-functionalized analogues by directly oxidizing oleic acid ligands with the Lemieux-von Rudloff reagent. This oxidation process has no obvious adverse effects on the morphologies, phases, compositions and luminescent capabilities of UCNPs. Furthermore, as revealed by Fourier transform infrared (FTIR) and NMR results, oleic acid ligands on the surface of UCNPs can be oxidized into azelaic acids (HOOC(CH2) 7COOH), which results in the generation of free carboxylic acid groups on the surface. The presence of free carboxylic acid groups not only confers high solubility in water, but also allows further conjugation with biomolecules such as streptavidin. A highly sensitive DNA sensor based on such streptavidin-coupled UCNPs have been prepared, and the demonstrated results suggest that these biocompatible UCNPs have great superiority as luminescent labeling materials for biological applications.
- Chen, Zhigang,Chen, Huili,Hu, He,Yu, Mengxiao,Li, Fuyou,Zhang, Qiang,Zhou, Zhiguo,Yi, Tao,Huang, Chunhui
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p. 3023 - 3029
(2008/09/19)
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- 2-Methoxybenzylidenepyruvatewith heavier trivalent lanthanides and yttrium(III): Synthesis and characterization
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Solid-state Ln(2-MeO-BP) compounds, where Ln stands for trivalent Eu to Lu and Y(III) and 2-MeO-BP (which is 2-methoxybenzylidenepyruvate) have been synthesized. Simultaneous thermogravimetry and differential thermal analysis (TG-DTA), differential scanni
- Ionashiro,Bannach,Siqueira,De Carvalho,Rodrigues,Ionashiro
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p. 953 - 959
(2009/02/01)
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- Synthesis, characterization and thermal behaviour of solid 2-methoxybenzoates of trivalent metals
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Solid-state Ln(L)3 compounds, where Ln stands for trivalent Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Y and L is 2-methoxybenzoate have been synthesized. Simultaneous thermogravimetry and differential thermal analysis (TG-DTA), differential scanni
- Siqueira,Carvalho,Ionashiro,Bannach,Rodrigues,Ionashiro
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p. 945 - 951
(2009/02/01)
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- Thermal and spectroscopic investigations of new lanthanide complexes with 1,2,4-benzenetricarboxylic acid
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The new 1,2,4-benzenetricarboxylates of lanthanide(III) of the formula Ln(btc)?nH2O, where btc is 1,2,4-benzenetricarboxylate; Ln is La-Lu, and n=2 for Ce; n=3 for La, Yb, Lu; and n=4 for Pr-Tm were prepared and characterized by elemental analy
- Lyszczek
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p. 533 - 539
(2008/10/09)
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- A systemic study of stepwise chlorination-chemical vapor transport characteristics of pure rare earth oxides from Sc2O3 to Lu2O3 mediated by alkaline chlorides as complex former
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A systematic study has been carried out for the stepwise chlorination-chemical vapor transport (SC-CVT) characteristics of pure rare earth oxides from Sc2O3 to Lu2O3 mediated by the vapor complexes KLnCl4 and NaLnCl4 (Ln = Sc, Y and La-Lu) used NaCl and KCl as complex former, respectively. The results showed that the SC-CVT characteristics are similarly for NaCl and KCl as complex former, the main deposition temperature of the rare earth chlorides LnCl3 is in the increasing order ScCl3 3 3, and then with a systematically decreasing trend from the early lanthanide chlorides to the end one. The results also showed that the total transported amount of the produced chlorides is YCl3 > ScCl3, and they are much higher than that of most lanthanoid chlorides. For lanthanoids, the total transported amount of chloride increases systematically from the early lanthanoid chlorides to the end one except for EuCl3 and GdCl3 mediated by KCl and NaCl as complex former, respectively, which showed the divergence effect of Gd in the total transport efficiency. But there are some differences in SC-CVT characteristics of pure rare earth oxide mediated by KCl and NaCl as complex former, that is the main deposition temperature region for the same rare earth element was lower for KCl than that for NaCl as complex former except for LaCl3, CeCl3, YbCl3 and LuCl3, while the total transport amount of rare earth chloride for KCl as complex former is higher than that for NaCl except for LaCl3 and EuCl3. More over, the discussion was carried out for Sc and Y on the one hand and the lanthanides contain 4f electron as another hand based on the 4f electron hybridization assumption. Further more, the transport characteristics of rare earth oxides with alkaline chlorides as complex former in this study were compared to that with AlCl3 as complex former.
- Sun, Yan-Hui,He, Peng,Chen, Hua-Ni
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p. 352 - 358
(2008/10/09)
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- Microcalorimetric studies on the interactions of lanthanide ions with bovine serum albumin
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The interactions of lanthanide ions (Ln3+) with bovine serum albumin (BSA) under mimetic physiological conditions (310.15 K, pH 6.7, 0.1MNaCl) were studied by microcalorimetry. For the first time, based on Two Sets of Independent Sites Model, m
- Li,Wang,Li,Wang
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p. 899 - 905
(2008/10/09)
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- Synthesis, characterization and thermal behaviour of solid-state compounds of yttrium and lanthanide benzoates
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Solid-state Ln(Bz)3?H2O compounds where Ln stands for trivalent yttrium or lanthanides and Bz is benzoate have been synthesized. Simultaneous thermogravimetry-differential thermal analysis (TG-DTA), X-ray powder diffractometry, infra
- Locatelli,Rodrigues,Siqueira,Ionashiro,Bannach,Ionashiro
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p. 737 - 746
(2008/10/09)
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- Synthesis, characterization and thermal behaviour of solid 4-methoxybenzoates of heavier trivalent lanthanides
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Solid-state Ln-4-MeO-Bz compounds, where Ln stands for trivalent Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Y and 4-MeO-Bz is 4-methoxybenzoate, have been synthesized. Simultaneous thermogravimetry and differential thermal analysis (TG-DTA), differential scan
- Rodrigues, Emanuel C.,Siqueira, Adriano B.,Ionashiro, Elias Y.,Bannach, Gilbert,Ionashiro, Massao
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p. 149 - 155
(2008/10/09)
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- Synthesis and structural diversity of rare earth anthranilate complexes
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Four structural classes have been established for rare earth anthranilates, which have been prepared from the lanthanoid chloride or triflate and anthranilic acid (anthH) followed by pH adjustment to 4. [La(anth) 3]n is a polymeric complex with nine coordinate lanthanum and bridging tridentate (O,O,O′) anthranilate ligands, whereas [Nd(anth)3(H2O)3]·3H2O is monomeric with nine coordinate neodymium and solely chelating (O,O) anthranilate groups. Both chelating (O,O) and bridging bidentate (O,O′) ligands are observed in dimeric [Er2(anth)6(H2O) 4]·2H2O, in which erbium is eight coordinate and the water ligands are in a trans arrangement. A polymer is observed for [Yb(anth)3(H2O)]n with solely bridging bidentate (O,O′) ligands and seven coordination for ytterbium. The NH 2 groups of the anthranilate ligands are not coordinated to the metal but is unusually involved in hydrogen-bond networks with water molecules for Ln = Er, Yb.
- Deacon, Glen B.,Forsyth, Maria,Junk, Peter C.,Leary, Stuart G.,Moxey, Graeme J.
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p. 379 - 386
(2008/10/09)
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- Synthesis, characterization and thermal studies on solid compounds of 2-chlorobenzylidenepyruvate of heavier trivalent lanthanides and yttrium(III)
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Solid-state compounds of general formula LnL3· nH 2O, where Ln represents heavier lanthanides and yttrium and L is 2-chlorobenzylidenepyruvate, have been synthesized. Chemical analysis, simultaneous thermogravimetry-differential anal
- Bannach,Schnitzler,Treu Filho,Utuni,Ionashiro
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p. 233 - 240
(2008/10/09)
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- Equilibria and structure of the lanthanide(III)-2-hydroxy-1,3- diaminopropane-N,N,N′,N′-tetraacetate complexes: Formation of alkoxo-bridged dimers in solid state and solution
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The complex formed between 1,3-diamino-2-hydroxypropane-N,N,N′, N′-tetraacetic acid (H4L-OH) and Nd3+ at pH 7.5 was found to be a dinuclear dimer in the solid state by X-ray crystallography. In the complex K4[Nd2(L-O)2-(H2O) 2]-14H2O each ligand is coordinated to both Nd 3+ atoms with an iminodiacetate group (the Nd3+-Nd 3+ distance is 3.9283(8) A). The alcoholic OH groups are deprotonated, and the alkoxo oxygens are coordinated to both Nd3+ in a bridging position. The Nd3+ ions are nine-coordinated with one water molecule per Nd(III) ion in the inner sphere. The complex K 4[Nd2(L-O)2(H2O)2] ·14H2O has an inversion center, and the space group is P1. Two of the K+ counterions are six-coordinated, while the other two K+ ions are eight-coordinated; polar polymeric water-K+ layers are formed between the apolar ligand layers via the bridging water molecules. The dinuclear dimer complexes are also present in aqueous solution. The proton relaxivities of the Gd3+ complex decrease with the increase of pH, and at pH > 6, the low relaxivity values indicate the probable absence of H2O in the inner sphere and the predominance of the eight-coordinated dimer species [Gd2(L-O)2]. 4- The results of ESI-TOF MS studies of the complexes of La 3+, Nd3+, and Lu3+ proved the formation of dinuclear dimers in dilute (0.25 mM) solutions. pH-potentiometric titrations indicate the formation of complexes with 1:1 (Ln(L-OH)-, Ln(HL-OH), and Ln2(L-O)24-) and 2:1 (Ln 2(L-O)+) metal-to-ligand ratios. The stability constants of the Ln(L-OH)- species increase from La3+ (log K = 10.19) to Lu3+ (log K = 14.08). The alcoholic OH group of the Ln(L-OH)- species dissociates at unusually low pH values. The pH range of dissociation shifts to lower and lower pH's with the increasing atomic number of the lanthanides. This pH range is about 4-7 for the La3+ complex and 1-4 for the Lu3+ complex. The results of 1D and 2D 1H and 13C NMR studies of the La3+ complex, the number and multiplicity of signals, and the values of coupling constants are in agreement with the dinuclear dimer structure of the complex in solution.
- Tircso, Gyula,Benyei, Attila,Bruecher, Erno,Kis, Anita,Kiraly, Robert
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p. 4951 - 4962
(2008/10/09)
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- Synthesis, characterization, thermal stability, reactivity, and antimicrobial properties of some novel lanthanide(III) complexes of 2-(N-salicylideneamino)-3-carboxyethyl-4,5,6,7-tetrahydrobenzo[b]thiophene
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Two series of new lanthanide(III) complexes of the type [Ln(HSAT) 2(H2O)3Cl3] and [Ln(HSAT) 2(NO3)3], where Ln = La, Pr, Nd, Sm, Eu, Gd, Dy, Tm, Yb, or Lu, and HSAT = 2-(N-salicy
- Mohanan,Devi
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p. 600 - 609
(2008/10/09)
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- Near-infrared luminescent hybrid materials doped with lanthanide (Ln) complexes (Ln = Nd, Yb) and their possible laser application
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The crystal structures of ternary Ln(DBM)3phen complexes (DBM = dibenzoylmethane, phen = 1,10-phenanthroline, and Ln = Nd, Yb) and their in situ syntheses via the sol-gel process are reported. The properties of the Ln(DBM)3phen complexes and their corresponding Ln3+/DBM/ phen-co-doped luminescent hybrid gels obtained via an in situ method (Ln-D-P gel) have been studied. The results reveal that the lanthanide complexes are successfully in situ synthesized in the corresponding Ln-D-P gels. Both Ln-(DBM)3phen complexes and Ln-D-P gels display sensitized near-infrared (NIR) luminescence upon excitation at the maximum absorption of the ligands, which contributes to the efficient energy transfer from the ligands to the Ln3+ ions (Ln = Nd, Yb), an antenna effect. The radiative properties of the Nd3+ ion in a Nd-D-P gel are discussed using Judd-Ofelt analysis, which indicates that the 4F3/2 a?? 4I11/2 transition of the Nd3+ ion in the Nd-D-P gel can be considered as a possible laser transition. ? 2005 American Chemical Society.
- Sun, Li-Ning,Zhang, Hong-Jie,Meng, Qing-Guo,Liu, Feng-Yi,Fu, Lian-She,Peng, Chun-Yun,Yu, Jiang-Bo,Zheng, Guo-Li,Wang, Shu-Bin
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p. 6174 - 6182
(2008/10/09)
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- Extraction of lanthanide chlorides by binary extractants based on phosphinic acid derivatives
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The extraction of lanthanide chlorides by methyltrioctylammonium dialkylphosphinate, dialkyl-monothiophosphinate, or dialkyldithiophosphinate in toluene was studied. In all cases, extractable MA3 compounds were formed in an organic phase. The extractability of metals increased in the order La a considerable effect on the distribution of the lanthanide salts. The extraction capacity of the binary extradants toward lanthanum chloride decreased in the order methyltrioctylammonium dialkylphosphinate > methyltrioctylammonium dialkylmonothiophosphinate > methyltrioctylammonium dialkyldithiophosphinate. Copyright
- Egorova,Belova,Voshkin,Zhilov,Khol'kin
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p. 1781 - 1784
(2008/10/09)
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- Lanthanide contraction and pH value controlled structural change in a series of rare earth complexes with p-aminobenzoic acid
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A series of rare earth complexes with p-aminobenzoic acid (HL) have been synthesized: [RE2L6(H2O)2] n [RE=La (1), Ce(2), Pr(3), Sm(4), Eu(5), Tb(6), Dy(7), Er(9)] and [RE2L6(H2O)4]·2H 2O [RE=Tb(6′), Ho(8), Yb(10), Lu(11), Y(12)]. The crystal structures of 1, 2, 6, 6′, 7, 9 and 12 have been determined and the isomorphous relationships of the others have been identified. Their structures change from two-dimensional (2D) array (the coordination number of the metal ions is nine for 1 and eight for 2-7 and 9) to double-nuclear structure (the metal ions are eight-coordinated) for 6′, 8 and 10-12, as controlled by lanthanide contraction. The structural type has been found influenced by the pH value of the reaction mixtures.
- Sun, Hao-Ling,Ye, Chao-Hong,Wang, Xin-Yi,Li, Jun-Ran,Gao, Song,Yu, Kai-Bei
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- Fullerides: Heterometallic superconductors with composition M2M′C60 (M = K, Rb; M′ = Yb, Lu, Sc)
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One- or two-step reactions of potassium and rubidium fullerides with composition Mk C60 (M = K, Rb; k = 3-6) and K 6C60 + m K mixtures (m = 1, 3) with anhydrous salts M′Cl3 (M′ = La, Pr, Nd, Sm, Gd, Tb, Yb, Lu, Y, Sc) and YbI2 in a toluene-THF medium afforded heterometallic fullerides M3- n M′n C60 (n = 1-3). Among these compounds, substituted fullerides with composition M2M′C60 (M′ = Yb, Lu, Sc) display superconducting properties with critical temperatures of 14-20 K.
- Bulychev,Lunin,Kul'bachinskii,Shpanchenko,Privalov
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p. 1686 - 1692
(2007/10/03)
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- Cooperative Yb3+-Tb3+ dimer excitations and upconversion in Cs3Tb2Br9:Yb3+
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Green Tb3+5D4→7FJ luminescence visible by eye is observed under near-infrared laser excitation. Optical spectroscopic techniques including absorption, luminescence, and excitation spectroscopy are used to characterize this upconversion (UC) luminescence. The Tb3+ UC luminescence is present for all temperatures within a range from 10 to 300 K, and gains intensity by three orders of magnitude between 10 and 300 K. For T ≥ 100 K the dominant upconversion mechanism is the cooperative sensitization of Tb3+ by two Yb3+ ions. In this temperature regime the Tb3+ UC luminescence dominates the visible (VIS) spectrum for all near-infrared (NIR) excitations, resulting in the characteristic green luminescence. At 10 K, the color of the luminescence changes from green to blue, depending on the excitation wavelength corresponding to the dominance of Tb3+ UC luminescence or the Yb3+-Yb3+ cooperative pair luminescence. Two color excitation spectroscopy is performed to directly observe an excited state absorption (ESA) step in the Tb3+ UC luminescence excitation spectrum at 10 K. This allows the unambiguous assignment of a type of ground state absorption/excited state absorption (GSA/ESA) mechanism responsible for the upconversion in this system at 10 K. We explain this cooperative interaction in the framework of an Yb3+-Tb3+ exchange-coupled dimer. An energy level diagram for this dimer is presented. Excitation into dimer levels around 12000-14500 cm-1, where neither Yb3+ nor Tb3+ single ions have levels, leads to Yb3+ luminescence at 10 K. For laser excitation, 53 W/mm2, resonant with an ESA transition a VIS/NIR photon ratio of 2.7(10)-5 is found at 10 K.
- Salley, G. M.,Valiente, R.,Guedel, H. U.
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- Synthesis, characterisation and thermal behaviour of solid stat compounds of 4-methylbenzylidenepyruvate with heavier trivalent lanthanides and yttrium(III)
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Solid state Ln-4-Me-BP compounds, where Ln stands for heavier trivalent lanthanides (gadolinium to lutetium) and yttrium(III) and 4-Me-BP is 4-methylbenzylidenepyruvate (CH3-C6H4-CH=CH-COCOO-), have been synthesized. Eleme
- Marques,Melios,Ionashiro
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p. 145 - 150
(2008/10/08)
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- Pyridinium chlorometallates of lanthanoid elements. Crystal structures of [HPy]2[LnCl5(Py)] with Ln = Eu, Er, Yb and of [H(Py)2][YbCl4(Py)2]·Py
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The pyridinium chlorometallates [HPy]2[LnCl5(Py)] with Ln = Eu, Er and Yb, as well as [H(Py)2][YbCl4(PY)2]·Py have been obtained by the reaction of diacetone alcohol with solutions of the corresponding metal trichlorides in pyridine at 100°C. According to the crystal structure determinations the anions [LnCl5(Py)]2- are linked by bifurcated Cl...H...Cl bridges with the protons of the [HPy]+ cations forming chains along [001]. The anions of [H(Py)2][YbCl4(Py)2]·Py form discrete octahedrons with trans-positions of the pyridine ligands. [HPy]2[EuCl5(Py)] (1a): Space group Pnma, Z = 4, lattice dimensions at -80°C: a = 1874.4(2), b = 1490.2(2), c = 741.5(1) pm, R1 = 0.0466. [HPy]2[ErCl5(Py)] (1b): Space group Pnma, Z = 4, lattice dimensions at -80°C: a = 1864.3(1), b = 1480.7(2), c = 739.7(1) pm, R1 = 0.0314. [HPy]2[YbCl5(Py)] (1c): Space group Pnma, Z = 4, lattice dimensions at -80°C: a = 1858.9(2), b = 1479.0(1), c = 736.8(1) pm, R1 = 0.0306. [H(Py)2][YbCl4(PY)2]·Py (2·Py): Space group Ia, Z = 4, lattice dimensions at -80°C: a = 1865.5(1), b = 827.5(1), c = 1873.4(1) pm, β = 103.97(1)°, R1 = 0.0258.
- Li, Jin-Shan,Neumueller, Bernhard,Dehnicke, Kurt
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p. 2785 - 2789
(2008/10/08)
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- Comparative study for stepwise chlorination-chemical vapor transport characteristics of pure rare earth oxides from Sc2O3 to Lu2O3 mediated by the vapor complexes LnAlnCl3n+3
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A systematic study has been carried out for the stepwise chlorination-chemical vapor transport (SC-CVT) characteristics of pure rare earth oxides from Sc2O3 to Lu2O3 mediated by the vapor complexes LnAlnCl3n+3 (where Ln = rare earth elements) under identical conditions. The results show that the total transported amount of the produced chlorides is the highest for YCl3; it is also high for ScCl3, but low for LaCl3, and then increases systematically from the early lanthanide chlorides to the end lanthanide chlorides except CeCl3, EuCl3 and GdCl3. The results also show that the main deposition temperature of the chlorides is in the increasing order ScCl3 3 3 and then with a systematically decreasing trend from the early lanthanide chlorides to the end lanthanide chlorides. Based on the literature data for the solid complexes LnAl3Cl12 and LnAl3Br12, a similar coordination structure assumption is introduced for the vapor complexes LnAl3Cl3n+3 from Ln = Sc to Ln = Lu with the same stoichiometry to explain the SC-CVT characteristics of the pure rare earth oxides from Sc2O3 to Lu2O3 using a 4f electron hybridization assumption.
- Wang, Zhi-Chang,Sun, Yan-Hui,Guo, Lei
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p. 109 - 113
(2008/10/08)
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- Synthesis, characterization and anticoagulant action of lanthanide complexes of warfarin
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Thirteen lanthanide complexes of warfarin, LnL3·nH2O [n = 6 (Ln = La-Yb) or n = 4 (Ln = Y); L = (C19H15O4)-] have been synthesized and characterized by elemental analyses, IR, 1H
- Jiao, Tian Quan,Wu, Ji Gui,Zeng, Fu Li,Fu, Yun Long,Deng, Ru Wen
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p. 725 - 735
(2008/10/09)
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- Interaction of thulium, ytterbium(III) and lutetium chlorides with sodium chloride
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The pseudobinary systems NaCl-LnCl3 (Ln = Tm, Yb, Lu) were investigated by DTA and X-ray diffraction. Two types of ternary chlorides exist: congruently melting compounds Na3LnCl6 with the cryolite-structure, incongruently melting compounds NaLnCl4 with the NaErCl4-Ln (Ln = Tm) or the NaLnCl4-structure (Ln = Yb, Lu). All these structure types contain [LnCl6]-octahedra. By solution calorimetry and e.m.f. measurements in galvanic cells for solid electrolytes could be proved that all compounds are formed from NaCl and LnCl3 by gain in lattice enthalpy.
- Buechel,Seifert
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p. 203 - 208
(2008/10/09)
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- Solution enthalpies of hydrates LnCl3·xH2O (Ln=Ce-Lu)
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Trichlorides of the lanthanide elements Ln=Ce-Lu form: (a) isotypic hexahydrates LnCl3·6H2O with a coordination number (CN) 8 for the Ln3+ ions. (b) Two isotypic groups of trihydrates LnCl3·3H2O, in the first group Ln=Ce-Dy the CN is 8; the structure of the second group Ln=Er-Lu is unknown. With Ho no trihydrate exists; a dihydrate is formed. (c) Two isotypic groups of monohydrates LnCl3·H2O with unknown structure - Ln=Ce-Dy and Ln=Ho-Lu. For all compounds and for anhydrous chlorides LnCl3 solution enthalpies were measured with an isoperibolic calorimeter. The ΔsolH0 values do not depend only on the difference (lattice enthalpies/hydration enthalpies), but also on the state in solution. According to Spedding the CN of the Ln3+ ions against water changes from 9 to 8 between Nd and Sm, causing minima in the series of solution enthalpies. Dihydrates LnCl3·2H2O are found for Ln=Ce, Pr, Nd, Sm and presumably for Eu and Gd. They are not yet well characterised.
- Seifert,Funke
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- Ternary chlorides in the systems ACl/YbCl3 (A=Cs,Rb,K)
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The phase diagrams of the ACl/YbCl3 (A=Cs,Rb,K) systems were investigated by DTA and XRD. Compounds A3YbCl6, A2YbCl5 and AYb2Cl7 exist in all systems, enneachlorides A3Yb2Cl9 in the systems with A=Cs,K. In the group AYb2Cl7, the Yb ions have coordination number 7, in all other compounds the coordination is octahedral. Thermodynamic functions determined by solution calorimetry and emf vs T measurements in galvanic cells for solid electrolytes reveal that the ternary chlorides AnYbCl3+n are stable compared with mixtures (nACl+YbCl3); the compounds Cs2YbCl5 and Rb2YbCl5 are stable only at temperatures >0 K.
- Sebastian, J?rg,Seifert, Hans-Joachim
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- IR Luminescence of Ytterbium Ions in Complexes with β-Fluorodiketones
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Spectroscopic and luminescence properties of Yb complexes with phenyl- and α-thienyl derivatives of acetylacetone are studied. The ligands are characterized by different chain lengths and structures of fluorocarbon groups (RF), which either contain or do not contain an oxygen heteroatom. β-Diketones with RF = C6F13 and C8F17 are synthesized for the first time. The influence of organic bases and solvents on the intensity of luminescence (I1) of ytterbium β-diketonates is studied. For Yb complexes, I1 is shown to correlate with such ligand characteristics as absorbance, length of the RF chain, and the sum of the Hammet constants σ* of the substituents.
- Topilova,Meshkova,Bol'shoi,Lozinskii,Shapiro
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- Thermal decomposition of rare earth complexes with 2-amino-3,5-dichlorobenzoic acid
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The conditions of the thermal decomposition of the 2-amino-3,5-dichloro-benzoates of Y and lanthanides have been studied. During heating in air, the dihydrated complexes Ln(C6H2Cl2NH2COO) 3·2H2/
- Mrozek,Sikorska,Rzaczynska
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p. 707 - 720
(2008/10/09)
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- Thermodynamic Properties of the Rare Earth Element Vapor Complexes LnAl3Cl12 from Ln = La to Ln = Lu
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Systematic analysis of rare earth element complexes has been carefully carried out in the liquid and solid states but not in the gaseous state because of the lack of a complete set of experimental data for any kind of vapor complexes of all rare earth elements. Here we present experimental quenching results which suggest that the LnAl3Cl12 complexes are the predominant vapor complexes roughly in the temperature range 588-851 K and pressure range 0.01-0.22 MPa for all of the 14 rare earth elements Ln = La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. For these elements, thermodynamic functions of the reactions LnCl3(s) + 3/2Al2Cl6(g) = LnAl3Cl12(g) were calculated from the measurements. Those for the radioelement Pm were smoothly interpolated. The results show Gd divergences from the standard enthalpies and standard entropies from LaAl3Cl12 to LuAl3Cl12.
- Wang, Zhi-Chang,Wang, Lin-Shan
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p. 1536 - 1540
(2008/10/09)
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- Lanthanide Ion Chelates of Dibenzyl 1,1'-Diacetylferrocenebis(hydrazonatocarbodithioate)
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A new ligand, dibenzyl 1,1'-diacetylferrocenebis(hydrazonatocarbodithioate), Fe[C5H4C(CH3)=NNHCSSCH2C6H5)2] (H2Dafhb) and its chelates with lanthanide ions, Ln(Dafhb)Cl (Ln = lanthanide) have been prepared by the reaction of the H2Dafhb with LnCl3. All compounds were characterized by elemental analyses, IR, (1H) NMR, UV, electrolytic conductivity and TGA measurements. It is shown that the ligand coordinates to the metal in the thiol form and that one chloride ion participates in coordination. The chelates are non-electrolytes in DMF and are more thermostable than the ligand due to formation of chelate rings.
- Gang, Zhao,Yuan, Cao
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p. 1207 - 1217
(2008/10/09)
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- LANTHANIDE COMPLEXES OF DI(4-HYDROXYCOUMARINYL-3)-ACETIC ACID AND THEIR ANTICOAGULANT ACTION
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The lanthanide complexes of di(4-hydroxycoumarinyl-3)-acetic acid (M2L3*10H2O) have been synthesized and characterized by IR, HNMR, electronic spectra, thermoanalysis and molar conductance.The metallic ions substituted two hydrogen atoms of carboxyl and hydroxy groups and are also bonded to the oxygen atom of the carbonyl group of the benzopyranyl ring.Electronic spectra showed that the lanthanide-ligand bond had some covalent character and the involvement of 4f orbital was very small.The light lanthanide complexes revealed the nice anticoagulant action especially the lanthanum coordination compound.
- Deng, Ru Wen,Wu, Ji Gui,Long, La Sheng
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p. 439 - 444
(2007/10/02)
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- Halide alkoxides of yttrium, gadolinium, erbium and ytterbium
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Reactions of yttrium, gadolinium, erbium and ytterbium isopropoxides with acetyl halides (chloride and bromide) in different molar ratios lead to respective halide isopropoxides containing increasing amounts of ester in the form of addition products.Chloride isopropoxides have also been prepared by radical interchange reactions between lanthanide trihalides and trisopropoxides.A typical 'gadolinium break' is observed in the solubilities of these products.The reactions of lanthanide t-butoxides with acetyl chloride are rather complex; the lanthanide chlorides formed initially tend to react with the side-product t-butyl acetate to form acetoxy derivatives, indicating an interesting variation with the change in the electronegativity values of the metals.
- Mehrotra, R.C.,Batwara, J.M.,Tripathi, U.D.,Tripathi, U.M.
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p. 793 - 798
(2007/10/02)
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- Organolanthanide and organoactinide oxidative additions exhibiting enhanced reactivity. 5. Stoichiometry, kinetic, and mechanistic studies of (C5Me5)2YbII·OEt2 oxidative-addition reactions and of (C5Me5)2YbIIIR (R = R, X) YbIII ...
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Full title: Organolanthanide and organoactinide oxidative additions exhibiting enhanced reactivity. 5. Stoichiometry, kinetic, and mechanistic studies of (C5Me5)2YbII·OEt2 oxidative-addition reactions and of (C5Me5)2YbIIIR (R = R, X) YbIII-Grignard reactions with alkyl and aryl halides. Evidence for the dominance of inner-sphere mechanisms. (C5Me5)2YbII·OEt 2 undergoes atom-abstraction oxidative addition with alkyl and aryl halides according to the generalized stoichiometry 1.0(C5Me5)2YbII·OEt 2 + (1 + a)RX → (1 - a)(C5Me5)2YbIIIX + (a)(C5Me5)1YbIIIX2 + (a)C5Me5R + 1.0Et2O + 1.0[R-R, R-H(alkanes), R(-H)(olefins)]. A reactive Yb-alkyl intermediate, (C5Me5)2YbIIIR, is formed from R? trapping by diamagnetic (C5Me5)2YbII. This (C5Me5)2YbIIIR intermediate and the initial product (C5Me5)2YbIIIX react further with RX in subsequent YbIII-Grignard reactions that are retarded by added Et2O and, therefore, apparently operate via an inner-sphere pathway. The observed YbIII-Grignard stoichiometries are (C5Me5)2YbIIIR + 2RX → (C5Me5)2YbIIIX2 + C5Me5R + R-R and (C5Me5)2YbIIIX + RX → (C5Me5)1YbIIIX2 + C5Me5R. The absolute rates of reaction of RX with (C5Me5)2YbII·OEt2 are found to be first-order each in (C5Me5)2YbII·OEt-2 and RX, with an added inverse dependence upon Et2O. The Et2O dependence is consistent with a requirement for a site of coordinative unsaturation and an inner-sphere pathway. Comparison of the rates of reactions of (C5Me5)2UIII(Cl)(THF) and (C5Me5)2YbII·OEt2 with RX provides compelling evidence for participation of electron transfer in these net atom-abstraction reactions.
- Finke,Keenan,Watson
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p. 263 - 277
(2008/10/08)
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