Reactions and phases within the TeO2-rich part of the Bi2O3-TeO2 system

The complexes of heavy lanthanides and yttrium with 2,3-dimethoxybenzoic acid of the formula: Ln(C₉h₉O₄)₃·nH₂O, where Ln=Tb(III), Dy(III), Ho(III), Er(III), Tm(III), Yb(III), Lu(III), Y(III), and n=2 for Tb(III), Dy(III), Ho(III), Y(III), n=1 for Er(III), Tm(III), n=0 for Yb(III) and Lu(III) have been synthesized and characterized by elemental analysis, ir spectroscopy, thermogravimetric studies and x-ray diffraction measurements. The complexes have colours typical for Lnł³⁺ ions (Tb(III), Dy(III), Tm(III), Yb(III), Lu(III), Y(III) - white; Ho(III) - cream and Er(III) - salmon). the carboxylate groups in these complexes are a symmetrical, bidentate, chelating ligand or tridentate chelating-bridging. they are isostructural crystalline compounds characterized by low symmetry. On heating in air to 1273 k the 2,3-dimethoxybenzoates of heavy lanthanides and yttrium decompose in various ways. The complexes of Tb(III), Dy(III), Ho(III), Er(III), Tm(III) and Y(III) at first dehydrate to form anhydrous salts which next are decomposed to the oxides of the respective metals. 2,3-dimethoxybenzoates of Yb(III) and Lu(III) are directly decomposed to oxides. When heated in nitrogen the hydrates also dehydrate in one step to form the anhydrous complexes that next form the mixture of carbon and oxides of respective metals or their carbonates. The solubility of the yttrium and heavy lanthanide 2,3-dimethoxybenzoates in water at 293 k is of the order of 10^-2 mol dm^-3. This revised version was published online in July 2006 with corrections to the Cover Date.     

Thermal and Spectral Features of Yttrium and Heavy Lanthanide Complexes with 2,4-dimethoxybenzoic Acid

The complexes of yttrium and heavy lanthanides with 2,4-dimethoxybenzoic acid of the formula: Ln(C₉H₉O₄)₃×nH₂O, where Ln=Tb(III), Dy(III), Ho(III), Er(III), Tm(III), Yb(III), Lu(III) and Y(III), n=2 for Tb(III), Dy(III), Ho(III), Er(III), Tm(III) and Y(III), and n=0 for Yb(III) and Lu(III), have been synthesized and characterized by elemental analysis, IR spectroscopy, themogravimetric studies, as well as X–ray and magnetic susceptibility measurements. The complexes have a colour typical of Ln ³⁺ salts (Tb, Dy, Tm, Yb, Lu, Y – white, Ho – cream, Er – pink). The carboxylate group in these complexes is a bidentate, chelating ligand. The compounds form crystals of various symmetry. 2,4-Dimethoxybenzoates of Yb(III) and Lu(III) are isostructural. 2,4-Dimethoxybenzoates of yttrium and heavy lanthanides decompose in various ways on heating in air to 1173 K. The hydrated complexes first lose water to form anhydrous salts and then decompose to the oxides of respective metals. The ytterbium and lutetium 2,4-dimethoxybenzoates decompose in one step to form Yb₂O₃ and Lu₂O₃. The solubilities of the 2,4-dimethoxybenzoates of yttrium and heavy lanthanides in water and ethanol at 293 K are of the order of: ^10–3 and 10^–3 –10^–2 mol dm^–3, respectively. The magnetic moments for the complexes were determined over the range of 77–298 K. They obey the Curie–Weiss law. The results show that there is no influence of the ligand field on the 4f electrons of lanthanide ions. This revised version was published online in August 2006 with corrections to the Cover Date.     

Thermal and spectral studies of 2,4,5-trimethoxybenzoates of heavy lanthanides(III) and yttrium(III)

2,4,5-Trimethoxybenzoates of Tb(III), Dy(III), Ho(III), Er(III), Tm(III), Yb(III), Lu(III) and Y(III) are crystalline, hydrated salts with colours typical for M(III) ions. The carboxylate group is a bidenate, chelating ligand. The complexes of Tb(III), Dy(III) and Ho(III) are dihydrates while those of Er(III), Tm(III), Yb(III), Lu(III) and Y(III) are trihydrates. These compounds are characterized by low symmetry. On heating in air to 1273 K, the 2,4,5-trimethoxybenzoates of heavy lanthanides(III) and yttrium(III) decompose in two steps. At first they dehydrate to form anhydrous salts which next are decomposed to the oxides of the respective metals. The values of the enthalpy of dehydration process were determined. The solubility in water at 293 K for all heavy lanthanides(III) and yttrium(III) are in the orders of 10^-3-10^-4 mol dm^-3. The magnetic moments of the complexes were determined in the temperature range 77-300 K.     

Thermal decompositions of heavy lanthanide aconitates

The conditions of thermal decomposition of Tb(III), Dy, Ho, Er, Tm, Yb and Lu aconitates have been studied. On heating, the aconitates of heavy lanthanides lose crystallization water to yield anhydrous salts, which are then transformed into oxides. The aconitate of Tb(III) decomposes in two stages. First, the complex undergoes dehydration to form the anhydrous salt, which next decomposes directly to Tb₄O₇. The aconitates of Dy, Ho, Er, Tm, Yb and Lu decompose in three stages. On heating, the hydrated complexes lose crystallization water, yielding the anhydrous complexes; these subsequently decompose to Ln₂O₃ with intermediate formation of Ln₂O₂CO₃.     

4-Chloro-2-methoxybenzoates of heavy lanthanides(III) and yttrium(III)

4-Chloro-2-methoxybenzoates of heavy lanthanides(III) and yttrium(III) were obtained as mono-, di-, tri-or tetrahydrates with metal to ligand ratio of 1:3 and general formula Ln(C₈H₆ClO₃)₃·nH₂O, where n=1 for Ln=Er, n=2 for Ln=Tb, Dy, Tm, Y, n=3 for Ln=Ho and n=4 for Yb and Lu. The complexes were characterized by elemental analysis, FTIR spectra, TG, DTA and DSC curves, X-ray diffraction and magnetic measurements. The carboxylate group appears to be a symmetrical bidentate chelating ligand. All complexes are polycrystalline compounds. The values of enthalpy, ΔH, of the dehydration process for analysed complexes were also determined. The solubilities of heavy lanthanide(III) 4-chloro-2-methoxybenzoates in water at 293 K are of the order of 10⁻⁴ mol dm⁻³. The magnetic moments were determined over the range of 76–303 K. The results indicate that there is no influence of the ligand field of 4f electrons on lanthanide ions and the metal ligand bonding is mainly electrostatic in nature.     

Synthesis,characterization and thermal behaviour of solid 2-methoxybenzoates of trivalent metals

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 scanning calorimetry (DSC), X-ray powder diffractometry, infrared spectroscopy and complexometry were used to characterize and to study the thermal behaviour of these compounds. The results provided information on the composition, dehydration, coordination mode, structure, thermal behaviour and thermal decomposition.     

4,4′-Dipyridyl and 2,2′-dipyridyl complexes of rare-earth perchlorates

4,4-Dipyridyl and 2,2-dipyridyl complexes of rare-earth perchlorates of the formulaLn(4-dipy)₈(ClO₄)₃HClO₄ · 4H₂O (Ln=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb, Lu, Y, 4-dipy=4,4-dipyridyl) andLn(2-dipy)₃(ClO₄)₃ · 6H₂O (Ln=Pr, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb, Lu, Y, 2-dipy = 2,2-dipyridyl) have been synthesized. The IR spectra of these compounds and other physical properties are discussed.

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4,4-Dipyridyl- und 2,2-Dipyridylkomplexe von Seltenerdmetallperchloraten

Zusammenfassung Es wurden 4,4-Dipyridylkomplexe des TypsLn(4-dipy)₈(ClO₄)₃HClO₄ · · 4 H₂O mitLn=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb, Lu, Y und 2,2-Dipyridylkomplexe des TypsLn(2-dipy)₃(ClO₄)₃ · 6 H₂O mitLn=Pr, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb, Lu und Y dargestellt. Die IR-Spektren und andere physikalische Eigenschaften werden diskutiert.

     

Extraction of rare earth elements with functionalized ionic liquid, 1,11-bis(1-methylimidazol-3-yl)-3,6,9-trioxaundecane bis(hexafluorophosphate)

Interfacial distribution of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y between aqueous solutions of their salts and solutions of functionalized ionic liquid, 1,11-bis(1-methylimidazol-3-yl)-3,6,9-trioxaundecane bis(hexafluorophosphate) has been studied. The stoichiometry of extracted complexes has been determined, the effect of HNO₃ concentration in aqueous phase on the efficiency of rare earth elements(III) recovery into organic phase has been considered.     

4,4′-Dipyridyl complexes of rare-earth thiocyanates

4,4-Dipyridyl complexes of rare-earth thiocyanates of the formulaLn(4-dipy)₂(NCS)₃·5H₂O (Ln = La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb, Lu, Y, 4-dipy = 4,4-dipyridyl) have been synthesized. The IR spectra of these compounds and other physical properties are discussed. The thermal decomposition of some compounds (in the order Gd ÷ Lu) has been investigated.

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4,4-Dipyridylkomplexe von Seltenerdmetallthiocyanaten

Zusammenfassung Es wurden 4,4-Dipyridylkomplexe des TypesLn(4-dipy)₂(NCS)₃·5H₂O mitLn = La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb, Lu und Y dargestellt. Die IR-Spektren und andere physikalische Eigenschaften werden diskutiert und die thermische Zersetzung von einigen Verbindungen (in der Reihe Gd ÷ Lu) untersucht.

     

Neue Pyridiniumchlorometallatverbindungen der Seltenerdelemente

Summary Reaction of the rare earth chlorides with pyridinium chloride in tetrahydrofuran (THF) under anhydrous conditions gave nearly insoluble precipitates of the composition (pyH)₃ RECl₆·THF (RE=La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Y, Er, Tm, Yb, and Lu). They were characterized by chemical analysis and IR spectroscopy; decompositionin vacuo was studied, yielding the hithero unknown complexes (pyH)₃ RECl₆ (RE=La, Ce, Pr, Sm, Tb, Ho, Y, Tm, and Lu).

     

Thermal behaviour of hydrated lanthanide complexes with heptanedioic acid

The multi-step dehydration and decomposition of trivalent lanthanum and lanthanide heptanediate polyhydrates were investigated by means of thermal analysis completed with infrared study. Further more, X-ray diffraction data for investigated heptanediate complexes of general stoichiometry Ln₂(C₇H₁₀O₄)₃.nH₂O (wheren=16 in the case of La, Ce, Pr, Nd and Sm pimelates,n=8 for Eu, Gd, Tb, Dy, Er and Tm pimelates,n=12 for Ho, Yb and Lu pimelates) were also reported.

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Zusammenfassung Mittels TG, DTG, DTA wurde in Verbindung mit IR-Methoden der mehrstufige Dehydratations- und der Zersetzungsvorgang der Polyhydrate der PimelinsÄuresalze von dreiwertigem Lanthan und dreiwertigen Lanthanoiden untersucht. Röntgendiffraktionsdaten der untersuchten Heptandiat-Komplexe mit der allgemeinen Formel Ln₂(C₇H₁₀O₄)₃ nH₂O (mitn=16 für Ln=La, Ce, Pr, Nd und Sm,n=8 für Ln=Eu, Gd, Tb, Dy, Er und Tm sowien=12 für Ln=Ho, Yb und Lu) werden ebenfalls gegeben.

     

Experimental and Theoretical Studies on the Magnetic Anisotropy in Lanthanide(III)‐Centered Fe3Ln Propellers

Compounds [Fe₃Ln(tea)₂(dpm)₆] ( Fe₃Ln ; Ln= Tb–Yb, H₃tea=triethanolamine, Hdpm=dipivaloylmethane) were synthesized as lanthanide(III)‐centered variants of tetrairon(III) single‐molecule magnets (Fe₄) and isolated in crystalline form. Compounds with Ln=Tb–Tm are isomorphous and show crystallographic threefold symmetry. The coordination environment of the rare earth, given by two tea^3? ligands, can be described as a bicapped distorted trigonal prism with D₃ symmetry. Magnetic measurements showed the presence of weak ferromagnetic Fe ??? Ln interactions for derivatives with Tb, Dy, Ho, and Er, and of weak antiferromagnetic or negligible coupling in complexes with Tm and Yb. Alternating current susceptibility measurements showed simple paramagnetic behavior down to 1.8 K and for frequencies reaching 10000 Hz, despite the easy‐axis magnetic anisotropy found in Fe₃Dy , Fe₃Er , and Fe₃Tm by single‐crystal angle‐resolved magnetometry. Relativistic quantum chemistry calculations were performed on Fe₃Ln (Ln=Tb–Tm): the ground J multiplet of Ln³⁺ ion is split by the crystal field to give a ground singlet state for Tb and Tm, and a doublet for Dy, Ho, and Er with a large admixture of m_J states. Gyromagnetic factors result in no predominance of g_z component along the threefold axis, with comparable g_x and g_y values in all compounds. It follows that the environment provided by the tea^3? ligands, though uniaxial, is unsuitable to promote slow magnetic relaxation in Fe₃Ln species.     

Multicolour Optical Coding from a Series of Luminescent Lanthanide Complexes with a Unique Antenna

The bis‐tetrazolate‐pyridine ligand H₂pytz sensitises efficiently the visible and/or near‐IR luminescence emission of ten lanthanide cations (Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb). The Ln^III complexes present sizeable quantum yields in both domains with a single excitation source. The wide range of possible colour combinations in water, organic solvents and the solid state makes the complexes very attractive for labelling and encoding.     

Solvent extraction of lanthanide ions with 1-phenyl-3-methyl-4-benzoyl-pyrazolone-5 (HPMBP), III: Extraction of gadolinium(III), terbium(III), dysprosium(III), holimum(III), and thulium(III) byHPMBP from aqueous solutions

Summary The solvent extraction behaviour of Gd(III), Tb(III), Dy(III), Ho(III), and Tm(III) has been investigated using 1-phenyl-3-methyl-4-benzoyl-pyrazolone-5 (HPMBP or HL) in carbon tetrachloride as the extractant. Depending on the concentration ofHPMBP in the organic phase the chelatesLnL ₃ [Ln(III)=Gd, Tb, Dy, Ho, Tm] and adductsLnL ₃ · HL [Ln(III)=Gd, Tb, Dy, Ho] were extracted. The extraction equilibrium constants (K _ex3 orK _ex4) for the formation ofLnL ₃ orLnL ₃ · HL and the two-phase stability constants of the chelates or adducts ( ₃ ^x , ₄ ^x ) have been evaluated.

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Extraktion von Seltenerdmetall-Ionen mit 1-Phenyl-3-methyl-4-benzoyl-prazolon-5(HPMBP), 3. Mitt.: Extraktion von Gd(III), Tb(III), Dy(III), Ho(III), und Tm(III) aus wäßrigen Lösungen

Zusammenfassung Die Extraktion von Gd(III), Tb(III), Dy(III), Ho(III), und Tm(III) mittels 1-Phenyl-3-methyl-4-benzoyl-pyrazolon-5 (HPMBP oderHL) in Kohlenstofftetrachlorid wurde untersucht. In Abhängigkeit von der Konzentration anHPMBP in der organischen Phase bildeten sich Chelate vom TypLnL ₃ [Ln(III)=Gd, Tb, Dy, Ho, Tm] and Addukte vom TypLnL ₃ · HL [Ln(III)=Gd, Tb, Dy, Ho]. Die Werte der Extraktions-Gleichgewichtskonstanten (K _ex3 oderK _ex4) fürLnL ₃ oderLnL ₃ · HL, sowie die Zweiphasen-Beständigkeitskonstanten ( ₃ ^x , ₄ ^x ) der Chelate oder Addukte wurden berechnet.

     

Thermal decomposition of rare earth element suberates in air atmosphere

The condition of thermal decomposition of La, Ce(III), Pr(III), Nd, Sm, Eu(III), Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu suberates were studied. The suberates of Ce(III), Sm, Eu(III), Ho, Tm, Yb and Lu heated lose crystallization water. Anhydrous Sm and Eu(III) suberates decompose to oxides with intermediate formation Ln₂O₂CO₃, whereas suberates of other lanthanides decompose directly to oxides. Suberates of La, Pr(III), Nd, Gd, Tb, Dy and Er lose some water molecules and then decompose directly to oxides. Only La complex decomposes to La₂O₃ via the intermediate formation La₂O₂CO₃.

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Zusammenfassung Es wurden die UmstÄnde der thermischen Zersetzung von La-, Ce(III)-, Pr(III)-, Nd-, Sm-, Eu(III)-, Gd-, Tb-, Dy-, Ho-, Er-, Tm-, Yb- und Lu-suberat untersucht. Bei Erhitzen verlieren Ce(III)-, Sm-, Eu(III)-, Ho-, Tm-, Yb- und Lu-suberat Kristallwasser. Wasserfreies Sm-bzw. Eu(III)-suberat zersetzt sich über das Zwischenprodukt der Zusammensetzung Ln₂O₂CO₃ zum Oxid, wÄhrend sich die Suberate der anderen Lanthanoide direkt zu den Oxiden zersetzen. La-, Pr(III)-, Nd-, Gd-, Tb-, Dy- und Er-suberat geben einige Moleküle Kristallwasser ab und zersetzen sich dann direkt zu den Oxiden. Nur der Lanthankomplex zersetzt sich zu La₂O₃ über das Zwischenprodukt La₂O₂CO₃.

     

Synthesis And Characterization Of Complexes Of Rare Earth Elements With 1,1-Cyclobutanedicarboxylic Acid

The complexes of yttrium and lanthanide with 1,1-cyclobutanedicarboxylic acid of the formula: Ln₂(C₆H₆O₄)₃⋅nH₂O, where n=4 for Y, Pr–Tm, n=5 for Yb,Lu, n=7 for La, Ce have been studied. The solid complexes have colours typical of Ln³⁺ ions. During heating in air they lose water molecules and then decompose to the oxides, directly (Y, Ce, Tm, Yb) or with intermediate formation. The thermal decomposition is connected with released water (313–353 K), carbon dioxide, hydrocarbons(538–598 K) and carbon oxide for Ho and Lu. When heated in nitrogen they dehydrate to form anhydrous salt and next decompose to the mixture of carbon and oxides of respective metals. IR spectra of the prepared complexes suggest that the carboxylate groups are bidentate chelating. This revised version was published online in August 2006 with corrections to the Cover Date.     

A Series of Rare-Earth Mesoionic Carbene Complexes

We report the synthesis and characterisation of a series of rare-earth mesoionic carbene complexes, [RE{N(SiMe₃)₂}₃{CN(Me)C(Me)N(Me)CH}] ( 3RE , RE=Sc, Ce, Pr, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu), greatly expanding the limited library of f-block mesoionic carbene complexes. These complexes were prepared by treatment of the parent RE-triamides with an N-heterocyclic olefin (NHO), where an NHO backbone proton undergoes a formal 1,4-proton migration to the NHO-methylene group. For all RE(III) metals, as expected, quantum chemical calculations suggest only a σ-component to the metal−carbene bonding, in contrast to a previously reported uranium(III) congener where the 5f³ metal engages in a weak π-back-bond to the MIC. All complexes were characterised by static variable-temperature magnetic measurements, and dynamic magnetic measurements reveal that 3Dy and 3Er are field-induced single-molecule magnets (SMMs), with U_eff energy barriers of 35 and 128 K, respectively. Complex 3Dy is, as expected, a poorly performing SMM, but conversely 3Er performs unexpectedly well.     

交流电弧中共存稀土元素对光谱线强度影响的研究

本工作较系统地研究了在交流电弧中不同量的共存稀土元素镝、钬，饵，铥和镱对某些被测稀土元素光谱线强度的影响。用交流电弧激发溶液干渣样品，其样品是在固定量的被测元素溶液中各自分别加入不同量的共存元素镝、钬、铒、铥和镱，摄谱后测量各被测元素的光谱线强度对共存元素在溶液中各个不同浓度作关系曲线。     

Extraction of rare-earth nitrates by phosphoryl podands

The distribution of trace amounts of rare-earth nitrates between aqueous solutions of NH₄NO₃ and organic solutions of phosphoryl podands is studied for Ln = La, Ce, Pr, Nd, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y. The stoichiometry of the extraction complexes is determined. The effect of the structure of the extractant and the nature of the organic solvent on the efficiency of rare-earth recovery to the organic phase is considered.     

Extraction of rare earth elements with 2-[2'-(methoxydiphenylphosphoryl)phenyldiazenyl]-4-<Emphasis Type="Italic">tert</Emphasis>-butylphenol in the presence of 1-butyl-3-methylimidazolium and trioctylmethylammonium picrates

Extraction of micro amounts of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y with solutions of 2-[2'-(methoxydiphenylphosphoryl)phenyldiazenyl]-4-tert-butylphenol in 1,2-dichloroethane in the presence of 1-butyl-3-methylimidazolium and trioctylmethylammonium picrates has been studied. The stoichiometry of extracted complexes has been determined, the effect of HNO₃ concentration in aqueous phase on the efficiency of rare earth elements recovery into organic phase has been considered.