- Synthesis, characterization and thermal behaviour of solid state compounds of 4-methylbenzylidenepyruvate with lighter trivalent lanthanides
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Solid state Ln-4-Me-BP compounds, where Ln stands for lighter trivalent lanthanides (lanthanum to europium) and 4-Me-BP is 4-methylbenzylidenepyruvate, have been synthesized. Elemental analysis, complexometry, X-ray powder diffractometry, infrared spectro
- Marques,Melios,Ionashiro
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- Phase equilibria in rare-earth chloride-fluoride and rare-earth chloride-magnesium fluoride systems
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Equilibrium phase diagrams for the systems LaCl3-LaF3, CeCl3-CeF3, NdCl3-NdF3, LaCl3-MgF2, CeCl2-MgF2, and NdCl3-MgF2 were determined by differential thermal analysis. A eutectic was observed at 654° ± 4°C and 31 molpercent LaF3 in the LaCl3-LaF3 system, 620° ± 3°C and 31.5 molpercent CeF3 in the CeCl3-CeF3 system, 615° ± 5°C and 29 molpercent NdF3 in the NdCl3-NdF3 system, 723° ± 5°C and 30 molpercent MgF2 in the LaCl3-MgF2 system, 690° ± 3°C and 26 molpercent MgF2 in the CeCl3-MgF2 system, and 655° ± 3°C and 26.5 molpercent MgF2 in the NdCl3-MgF2 system. A compound, NdCl3·NdF3, decomposing at 595° ± 5°C, also was observed in the NdCl3-NdF3 system. On the basis of agreement between the activities calculated by the Temkin model and the Clausius-Clapeyron equation, the melts of the rare-earth (RE) chloride and fluoride consisted of RE3+, Cl-, and F-. The melts formed with a rare-earth chloride and magnesium fluoride consisted of RE3+, Mg2+, RECl63-, and MgF42-.
- Sharma, Ram A.
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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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- 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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- Low-temperature heat capacity and thermodynamic properties of crystalline [RE (Gly)3(H2O)2]Cl3 ·2H2O (RE = Pr, Nd, Gly = Glycine)
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Heat capacities of two solid complexes of rare-earth elements with glycine [RE(Gly)3(H2O)2]Cl3 ·2H2O (RE = Pr, Nd, Gly = Glycine) have been measured with a high-precision automatic adiabatic calorimeter over the temperature range from 78 to 380 K. The melting point, molar enthalpy and entropy of fusion for the two complexes were determined on the basis of the heat capacity measurements. Thermal decompositions of the two complexes were studied by thermogravimetric (TG) techniques and a possible mechanism for the decompositions is suggested.
- Liu, Beiping,Tan, Zhi-Cheng,Lu, Jilin,Lan, Xiao-Zheng,Sun, Lixian,Xu, Fen,Yu, Ping,Xing, Jun
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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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- Photoacoustic phase study on the frequency dependence of phase angle and triplet state lifetime of Nd(III)-acetylacetonate
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The amplitude and phase of the photoacoustic (PA) signal generated in the rare earth complex powder of Nd(III)-acetylacetonate (Nd(AA)3) were examined. By using the reasonably simplified formula about phase angle at the wavelengths assigned to π-π* transition of ligand and f-f transitions of Nd3+, the instrumental contribution to phase angle at different chopping frequency was calculated. The frequency dependence of sample phase angle, the relative phase angle shift caused by instrumental factors and the calculation of triplet state lifetime of sample under study were also discussed. Being independent of sample, the instrumental contribution to phase angle was regarded as a parameter representing the situations of instruments and measurement and it became an approach to calculate the relaxation time of ligand in rare earth complex.
- Hu, Bin,Chen, Da,Su, Qingde
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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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- 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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- The Investigation of Conductivity of Liquid NdCl3-LiCl-KCl System by Mixture Design
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Scheffe' simplex centroid design and alternating electric bridge method have been used to design an experiment and to measure the conductivity of the rare earth molten salt system NdCl3-LiCl-KCl.The results are presented in the form of a regression equation between composition and conductivity, as well as in the form of an isogram of conductivity for the ternary system.
- Yifeng, Zhang,Dianpeng, Sui,Xuebing, Huang,Shulan, Wang
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- Comparative study of the mutual separation characteristics for binary mixed oxides Er2O3-Ln2O3 (Ln = Sc, Y, La, Nd, Sm, Gd and Ho) mediated by vapor complexes KLnCl4
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Mutual separation characteristics for a series of rare earth elements Sc, Y, La, Nd, Sm, Gd, Ho and Er from their binary oxide mixtures Er 2O3-Sc2O3, Er2O 3-Y2O3, Er2O3-La 2O3, Er2O3-Nd2O 3, Er2O3-Sm2O3, Er 2O3-Gd2O3 and Er2O 3-Ho2O3 has been investigated using a stepwise chlorination-chemical vapor transport (SC-CVT) reaction mediated by vapor complexes KLnCl4. The total transported yield of the chlorides produced from the oxide mixtures was in the order of ErCl3 > ScCl3, ErCl3 > YCl3, ErCl3 > LaCl3, ErCl3 > NdCl3, ErCl3 > SmCl3, ErCl3 > GdCl3 and HoCl3 > ErCl3, and the total separation factors are 13.0 for Er:Sc, 1.49 for Er:Y, 1.48 for Er:La, 1.15 for Er:Nd, 2.33 for Er:Sm, 2.72 for Er:Gd and 1.10 for Ho:Er. The largest separation factors 1213.8 for Er:Sc, 6.37 for Er:Y, 189.3 for Er:La, 100.6 for Er:Nd, 105.7 for Er:Sm, 27.8 for Er:Gd and 1.14 for Er:Ho in the lower temperature region, while 102.7 for La:Er, only 14.3 for Nd:Er, 16.7 for Sm:Er, 4.0 for Gd:Er and 2.04 for Ho:Er in the higher temperature region were observed, respectively. The results showed the obvious divergence effect of Gd both in the largest separation factors, the total separation factors and total transport efficiency. Furthermore, the results were discussed on the difference of ionic radius of Sc and Y on the one side and the lanthanoid elements of La, Nd, Sm, Gd, Ho and Er on the other hand, and verified that the ionic radius is one of the decisive factors only for lanthanide elements, not for Sc and Y.
- Sun, Yan-Hui,Chen, Zhen-Fei,Hu, Sheng-Liang
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- Preparation and characterization of rare earth orthoborates, LnBO 3 (Ln = Tb, La, Pr, Nd, Sm, Eu, Gd, Dy, Y) and LaBO3:Gd, Tb, Eu by metathesis reaction: ESR of LaBO3:Gd and luminescence of LaBO3:Tb, Eu
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Lanthanide orthoborates of composition LnBO3 (Ln = Tb, La, Pr, Nd, Sm, Eu, Gd, Dy, Y) and LaBO3:Gd, Tb, Eu have been prepared by metathesis reaction. This method provides a convenient route for the synthesis of orthoborates and its solid solutions at low temperatures. Powder X-ray diffraction and FT-IR spectroscopy were used to characterize these borates. Rare earth borates, (LnBO3) are isomorphous with different forms of CaCO3 depending on the radius of rare earth ion. LaBO3, LaBO3:Gd, Tb, Eu, PrBO3, NdBO3 crystallized in aragonite structure, SmBO3 crystallized in H-form and TbBO 3, EuBO3, GdBO3, DyBO3, YBO 3 crystallized in vaterite structure. The structural analysis of TbBO3 was carried out. The morphology of these borates was obtained from Scanning electron microscopy. Spin-Hamiltonian parameters for Gd 3+ are deduced from room temperature electron spin resonance spectrum of LaBO3:Gd. The luminescence of LaBO3:Tb, Eu gave characteristics peaks corresponding to Tb3+, Eu3+ respectively.
- Velchuri, Radha,Kumar, B. Vijaya,Devi, V. Rama,Prasad,Prakash, D. Jaya,Vithal
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- Properties of double chlorides in the systems ACl/NdCl3(A=Na-Cs)
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The pseudobinary systems ACl/NdCl3(A=Na-Cs) were reinvestigated by means of DTA. With a galvanic cell for solid electrolytes the thermodynamic functions of formation from ACl and NdCl3 together with the free enthalpies of synproportionation from the compounds adjacent in the phase diagrams were measured. They revealed, that only the compounds A2NdCl5 are stable at ambient temperature. All other compounds are existing by a gain of entropy only at higher temperatures. The crystal structures of the compounds were determined by X-ray analysis on powders: the compounds are isotypic with the analogous double chlorides of La and Ce.
- Seifert,Fink,Uebach
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- Synthesis and characterization of lanthanide(III) Schiff base complexes derived from cysteine and benzoin
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Six new complexes of the Schiff base ligand (HL) derived from benzoin and cysteine with Ln=La(III), Pr(III), Nd(III), Sm(III), Eu(III) and Gd(III) of the type LnLCl2(H2O)2 have been synthesized and characterized by element
- Ma,Wang,Shi
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- Relationships between structure and spectroscopic properties of Nd 3+ ethylenediaminetetramethylenephosphonates and ethylenediaminetetraacetates
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The structural and spectroscopic properties of the Nd3+ compounds [C(NH2)3]7[Nd(EDTMP)(CO 3)]·10H2O, K17H3[Nd 4(EDTMP)4]·36H2O, [C(NH 2)3][Nd(EDTA)(H2O)3] and Na[Nd(EDTA)(H2O)3]·5H2O are presented (H4EDTA = ethylenediaminetetraacetic acid, H8EDTMP is a phosphonic acid analogue of H4EDTA). The obtained monomeric [Nd(EDTMP)(CO3)]7- and tetrameric [Nd4(EDTMP) 4]20- structures, in which bidentate carbonate and tridentate bridged phosphonate coordination patterns appear, are exceptional. The use of different countercations has allowed us to assess their role in crystal formation and their influence on the spectroscopic properties of the investigated crystals. The countercations slightly change the geometry of [Nd(EDTA)(H2O)3]- and some subtle modifications of the geometry of the carboxylic groups is observed. These changes are discussed in the context of hypersensitive transition intensities. The intensities of the f-f transitions in all studied crystals were determined and analyzed basing on the Judd-Ofelt theory. Luminescence of the Nd3+ ions in the NIR region could be observed solely in the phosphonate complexes. The luminescence quantum yields were calculated from the luminescence lifetimes and the Judd-Ofelt parameters. The Φ value for the rigid tetramer [Nd 4(EDTMP)4]20- is twice as large (7 %) as that for the monomer [Nd(EDTMP)(CO3)]7- (3.5 %). The influence of different countercations on the structural and spectroscopic properties of Nd3+ complexes with ethylenediaminetetraacetic acid (EDTA) and its phosphonate analogue ethylenediaminetetramethylenephosphonic acid (EDTMP) are discussed. The absence of water molecules in the inner coordination spheres of the Nd3+ ions in the phosphonates is a reason for the efficient near-IR (NIR) f-f luminescence of the Nd3+-EDTMP crystals. Copyright
- Janicki, Rafal,Mondry, Anna
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- The oxide nitride selenides M3ONSe2 of trivalent lanthanoids (M = Ce - Nd)
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Oxide nitride selenides of the trivalent lanthanoids (M = Ce - Nd) with the composition M3ONSe2 can be prepared by the oxidation of the respective lanthanoid metal with selenium and sodium azide (NaN3) in presence of impurities containing oxygen when the corresponding lanthanoid trichloride (MCl3) is used as sodium trap for the coformation of NaCl. The thermal treatment of these mixtures along with additional NaCl as flux at 900°C in evacuated silica tubes secures the formation of fawn, transparent, lath-shaped crystals. The monoclinic structure (C2/m, Z = 6) was determined from X-ray single-crystal diffraction data (Ce3ONSe 2: a = 2480.51(14), b = 406.85(3), c = 952.83(6) pm, β = 95.506(4)°; Pr3ONSe2: a = 2462.72(14), b = 403.74(3), c = 947.26(6) pm, β = 95.731(4)°; Nd3ONSe2: a = 2440.35(14), b = 401.48(3), c = 944.02(6) pm, β = 95.763(4)°). Five crystallographically different M3+ cations reside in six- to eightfold coordination of the respective anions (three independent O 2-/N3- and Se2- each), for which a statistic distribution of the light elements (O2- : N3- = 1 : 1) has to be assumed. However, the main features of the crystal structure are (O 2-/N3-)-centred (M3+)4 tetrahedra. For the first time ever within the same structure of this kind, condensation of these anion-centred cation polyhedra forming strands and layers simultaneously could be detected. Cis-edge connected [(O/N)M4]9.5+ tetrahedra build up the chain components ∞1{[(O/N) (M4)3/3(M5)1/1]3,5+} running along [010], which are already known as dominating core in some crystal structures of pure nitride chalcogenides (e.g. Sm4N2S3 and Tb 4N2Se3). A new motif of condensed tetrahedral units comprises the second feature. By fusing [(O/N)M4] 9.5+ tetrahedra via vertices and edges, one-dimensional strand sections from the cationic sheets ∞2{([OCe 4/4]+)2} of the Ce2O 2S-type structure, which are further connected only via common vertices to form a lower-condensed steplike two-dimensional layer ∞2{[(O/N)4M5]5+}, spreading parallel to the (100) plane, emerge for the very first time.
- Lissner, Falk,Schleid, Thomas
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- Electronic absorption spectra of lanthanides in a molten chloride: II. Absorption characteristics of neodymium(III) in various molten chlorides
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Electronic absorption spectra of trivalent neodymium in LiCl-KCl eutectic, NaCl-2CsCl eutectic, CaCl2, LiCl, CsCl and mixtures of these at various temperatures were measured, and the variation of the absorption bands, 4G5/2, 2G7/2 ← 4I9/2, were carefully analyzed. The dependence of their molar absorptivity, oscillator strength, and the degree of the energy splitting on temperature and melt composition were determined. As a result, it was suggested that the NdCl63- complex keeps its octahedral symmetry in the NaCl-2CsCl eutectic, while this symmetry is more distorted in LiCl and CaCl2. Based on these data, the chemical status of NdCl 63- complex in molten chlorides was discussed.
- Fujii, Toshiyuki,Nagai, Takayuki,Sato, Nobuaki,Shirai, Osamu,Yamana, Hajimu
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- Mutual Separation Characteristics for Lanthanoid Elements via Gas Phase Complexes with Alkaline Chlorides
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Mutual separation characteristics of lanthanoid chlorides LnCl3 (Ln = Pr, Nd) using a chemical vapor transporting method via gaseous complexes were investigated.Compared with AlCl3 as the transporting agent, alkaline chlorides can transport more amounts of LnCl3, and enhance the separation efficiency between PrCl3 and NdCl3.
- Adachi, Gin-ya,Murase, Kuniaki,Shinozaki, Kiyoshi,Machida, Ken-ichi
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- Synthesis, characterization and thermal behaviour of solid-state compounds of light trivalent lanthanide succinates
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Characterization, thermal stability and thermal decomposition of light trivalent lanthanide succinates, Ln2(C4H4O4)3 ·nH2O (Ln = La to Gd, except Pm) were investigated employing simultaneous thermogravimetry and differential thermal analysis (TG-DTA), differential scanning calorimetry (DSC), infrared spectroscopy, TG-FTIR system, elemental analysis and complexometry. The dehydration of the lanthanum and cerium compounds occurs in a single step, while for the praseodymium to gadolinium compounds the dehydration occurs in two consecutive steps. The thermal decomposition of the anhydrous compounds occurs in consecutive and/or overlapping steps, except for the cerium compound, with formation of the respective oxides, CeO2, Pr6O11 and Ln2O3 (Ln = La, Nd to Gd), as final residue. The results also provided information concerning the denticity of the ligand and thermal behaviour of these compounds.
- Lima,Caires,Carvalho,Siqueira,Ionashiro
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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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- 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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- Synthesis, thermal properties and spectroscopic study of solid mandelate of light trivalent lanthanides
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Characterization, thermal stability and thermal decomposition of light trivalent lanthanide mandelates Ln(C6H5CH(OH)CO 2)3·nH2O (Ln = La to Gd, except Pm) were investigated employing simultaneous thermogravimetry and differential thermal analysis (TG-DTA), differential scanning calorimetry (DSC), experimental and theoretical infrared spectroscopy, elemental analysis, X-ray diffractometry, complexometry and TG-DSC coupled to FTIR. The dehydration of the lanthanum, samarium, europium and gadolinium compounds occurs in a single step while for praseodymium and neodymium ones it occurs in two consecutive steps. The thermal decomposition of the anhydrous compounds occurs in three, four or five consecutive steps, with formation of the respective oxides CeO2, Pr6O11 and Ln2O3 (Ln = La, Nd to Gd) as final residues. The results also provide information concerning the composition, thermal behavior and gaseous products evolved during the thermal decomposition of these compounds. The theoretical and experimental spectroscopic data suggest the possible modes of coordination of the ligand with the lanthanum.
- Gigante,Gomes,Lima,Caires,Treu-Filho,Ionashiro
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- Solubility behavior of rare earths with ammonium carbonate and ammonium carbonate plus ammonium hydroxide: Precipitation of their peroxicarbonates
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The purpose of this work is to report the significant behavior of the rare earths when treated with ammonium carbonate and with a binary mixture of ammonium carbonate plus ammonium hydroxide. The carbonates of some rare earths are completely soluble in ammonium carbonate or in ammonium carbonate plus ammonium hydroxide, while others are only partially soluble and finally some are completely insoluble. Addition of hydrogen peroxide to the soluble complexed rare earth carbonates results in the precipitation of a series of a new compounds described as rare earth peroxicarbonates. The rare earths have some different precipitation behavior in the carbonate-peroxide system. Some are completely and immediately precipitated, others are completely precipitated after an aging period, and finally other are not precipitated at all. These different behaviors open a new possibility for the separation chemistry of the rare earths. Sm, Gd, Dy, Y, Yb and Tm are fast and completely soluble in ammonium carbonate. Ho, Eu and Tb are completely soluble in ammonium carbonate but slowly dissolved. La, Ce, Pr and Nd are only partially soluble in ammonium carbonate. While Ce, Pr, Nd, Sm, Eu and Dy are completely and easily soluble in the ammonium carbonate plus ammonium hydroxide mixture, La is only partially soluble and Tb is completely insoluble in the same mixture. Concerning the peroxicarbonates, La, Ce, Pr, Nd, Sm, Eu, Gd, Dy and Ho are quantitatively precipitated. The precipitation of the Er peroxicarbonate is quantitative, but after an aging period of 24 h. Y is not precipitated at all. The process is very easy, simple and economically attractive. Although proved in bench scale, its scale-up is easily feasible.
- de Vasconcellos, Mari E.,da Rocha,Pedreira,Queiroz, Carlos A. da S.,Abr?o, Alcídio
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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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- 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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- Solid-state 2-methoxybenzoates of light trivalent lanthanides : SSSynthesis, characterization and thermal behaviour
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Solid-state LnL3 compounds, where L is 2-methoxybenzoate and Ln is light trivalent lanthanides, have been synthesized. Thermogravimetry (TG), differential scanning calorimetry (DSC), X-ray powder diffractometry, infrared spectroscopy and elemen
- Siqueira,Bannach,Rodrigues,Carvalho,Ionashiro
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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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- Exhaustive removal of thorium and uranium traces from neodymium by liquid extraction
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The Th content in commercially available Nd2O3 samples with the main substance content of 99.0-99.998% was found to be 2-8, and that of U, 3-230 ppb. Therefore, to obtain Nd meeting the requirements of the experiment on studying neutrinoless double β-decay, it should be purified to reduce the content of Th and U impurities by a factor of 10 3-104. To this end, the extraction of Nd, Th, and U from hydrochloric acid media with solutions of trioctylphosphine oxide (TOPO) in toluene was studied. The distribution ratios of Th increase with a decrease in the HCl concentration in the initial aqueous solution. With an increase in the Cl- concentration in the aqueous phase, the U distribution ratios decrease, probably because of a decrease in the concentration of the free extractant due to the extraction of Nd and HCl. On the contrary, the distribution ratios of Th increase with an increase in the Cl- concentration in the aqueous phase, with the slope of the straight line in the coordinates logDTh-log[Cl-]aq close to 7, which may be due to coextraction of Th with Nd in the form of the complex ThNdCl 7. The enthalpies of formation of the extractable complexes of Th and U were determined from the temperature dependence of the extraction of Nd, Th, and U chlorides with a 0.1 M solution of TOPO in toluene. The optimal extraction system was chosen for Nd purification to remove traces of Th and U: organic phase, 0.1 M solution of TOPO in toluene; aqueous phase, 2.4 M NdCl3 + 0.1 M HCl. From the initial aqueous solution contaning 574 ppt Th and 2837 ppt U, by single extraction with an equal volume of 0.1 M TOPO in toluene, an aqueous solution containing 3 solution containing 200 ppb Th, the raffinate containing 10 ppt Th was obtained in one extraction step. The results obtained confirm the possibility of exhaustive removal of Th and U impurities (to the level of ≤1 ppt) from Nd by extraction with TOPO solutions from chloride solutions.
- Danilov,Krylov,Zhilov,Tsivadze,Sal'Nikova,Barabanov,Bezrukov,Novikova,Yanovich,Cattadori,Nisi,Di Vacri,Salvo,Ianni
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- Synthesis, characterization and thermal behavior on solid tartrates of light trivalent lanthanides
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Solid state Ln-L compounds, where Ln stands for light trivalent lanthanides (L-Gd) and L is tartrate, have been synthesized. Thermogravimetry and differential thermal analysis (TG/DTA), differential scanning calorimetry (DSC), X-ray powder diffractometry,
- Ambrozini,Dametto,Siqueira,Carvalho,Ionashiro
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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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- Preparation, stability and thermodynamic properties of Nd- and Lu-doped BaCeO3 proton-conducting ceramics
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The preparation of BaCeO3 doped by neodymium and lute-tium oxides (BaCe0.8Nd0.2O2.9, BaCe 0.8Lu0.2O2.9) has been performed by solid-state reactions of BaCO3 and CeOsu
- Matskevich, Nata I.,Wolf, Thomas,Matskevich, Mariya Yu.,Chupakhina, Tatiana I.
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- Synthesis and characterization of volatile, fluorine-free β-ketoiminate lanthanide MOCVD precursors and their implementation in low-temperature growth of epitaxial CeO2 buffer layers for superconducting electronics
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A new class of volatile, low-melting, fluorine-free lanthanide metal-organic chemical vapor deposition (MOCVD) precursors has been developed. The neutral, monomeric Ce, Nd, Gd, and Er complexes are coordinatively saturated by a versatile, multidentate ether-functionalized β-ketoiminato ligand series, the melting point and volatility characteristics of which can be tuned by altering the alkyl substituents on the keto, imino, and ether sites of the ligand. Direct comparison with conventional lanthanide β-diketonate complexes reveals that the present precursor class is a superior choice for lanthanide oxide MOCVD. Epitaxial CeO2 buffer layer films can be grown on (001) YSZ substrates by MOCVD at significantly lower temperatures (450-650 °C) than previously possible by using one of the newly developed cerium β-ketoiminate precursors. Films deposited at 540 °C have good out-of-plane (Δω = 0.85°) and in-plane (Δφ = 1.65°) alignment and smooth surfaces (rms roughness ~ 4.3 A). The film growth rate decreases and the films tend to be smoother as the deposition temperature is increased. High-quality yttrium barium copper oxide (YBCO) films grown on these CeO2 buffer layers by pulsed organometallic molecular beam epitaxy exhibit very good electrical transport properties (Tc = 86.5 K, Jc = 1.08 x 106 A/cm2 at 77.4 K).
- Edleman, Nikki L.,Wang, Anchuan,Belot, John A.,Metz, Andrew W.,Babcock, Jason R.,Kawaoka, Amber M.,Ni, Jun,Metz, Matthew V.,Flaschenriem, Christine J.,Stern, Charlotte L.,Liable-Sands, Louise M.,Rheingold, Arnold L.,Markworth, Paul R.,Chang, Robert P. H.,Chudzik, Michael P.,Kannewurf, Carl R.,Marks, Tobin J.
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- Thermal decomposition kinetics and mechanism of lanthanide perchlorate complexes of 4-N-(4′-antipyrylmethylidene)aminoantipyrine
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The thermal decomposition behaviour of lanthanide perchlorate complexes of the Schiff base, 4-N-(4′-antipyrylmethylidene)aminoantipyrine (AA), have been studied using TG and DTG analyses. The phenomenological and kinetic aspects of the TG curves are inves
- Nair, M.K. Muraleedharan,Radhakrishnan
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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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- 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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- Internal cation mobility in molten LiCl-NdCl3 system
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Internal mobilities of Li+ and Nd3+ cations have been investigated in binary unsymmetrical molten LiCl-NdCl3 system by countercurrent electromigration method (so-called Klemm method). The results have been presented as isotherms of cation internal mobilities versus equivalent fraction of NdCl3 for 1023, 1073 and 1123 K and have been compared with corresponding relationships for NaCl-NdCl3 and KCl-NdCl3 systems. It has been found that internal mobility of Nd3+ ions (as well as Li+) increases with decreasing concentration of NdCl3, contrary to KCl-NdCl3 and NaCl-NdCl3 systems for which Nd3+ internal mobility decreases or is nearly constant, respectively. The tendency that smaller alkali metal cation enhances internal mobility of trivalent ion (bLn) has been described with a simple equation: bLn = bLn0 + a (1 - yLnC l3)2, where bLn0 is the internal mobility of Ln3+ in molten LnCl3, yLnC l3 the equivalent fraction of LnCl3 and a parameter is the difference between internal mobility of Ln3+ cation in molten LnCl3 and internal mobility of this cation in infinitely diluted solution of LnCl3 in alkali metal chloride.
- Zab?ocka-Malicka, Monika,Ciechanowski, Bart?omiej,Szczepaniak, W?odzimierz,Gawe?, Wies?aw
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- Structural and spectroscopic studies of neodymium complexes with S(+)-mandelic acid
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The crystal structure of tetraaquahexakis-S(+)-mandelatodineodymium trishydrate was determined by the X-ray diffraction method. The compound crystallizes in the monoclinic space group P21 with the following unit cell parameters: a = 10.536(2),
- Babij, Micha?,Starynowicz, Przemys?aw,Mondry, Anna
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- Synthesis, Characterization and thermal behaviour of hemimellitic acid complexes with lanthanides(III)
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The complexes of lanthanides(III) with hemimellitic acid (1,2,3-benzenetricarboxylic acid, H3btc) of the formula Ln(btc)?nH2O, where Ln=lanthanide(III) ion and n=2-6 were prepared and characterized by elemental analysis, infrared spe
- Lyszczek
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- Lanthanide complexes with 1,1′-diactylferrocene bis-2-furoylhydrazone
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A ligand, 1,1′-diacetylferrocene bis-2-furoylhydrazone (H 2Bafh), and its lanthanide [Ln(III)] complexes, [Ln(H 2Bafh)3]·(ClO4)3· nH2O [complexes A: Ln = La(III), Gd(III), Tm(III), Yb(III)], and [Ln(H2Bafh)Cl2]-Cl·nH2O [complexes B: Ln = Y(III), La(III), Nd(III), Gd(III), Tm(III)] were prepared and characterized by microanalyses, IR, 1H NMR, and UV-VIS spectra, molar conductivity, and TGA analyses.
- Song, Qing-Bao,Qiang, Gen-Rong,Shen, Tian-Hua,Yang, Zhen-Ping,Liang, Yong-Min,Wu, Xiao-Li,Ma, Yong-Xiang
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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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- 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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- Thermochemical investigations on the systems RE2O3-SeO2 IV. Solution calorimetry of the phases RE2SexO3+2x (RE = Nd, Sm, Y)
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The solution enthalpies have been determined for the ternary phases RE2SexO3+2x existing on the pseudo-binary section RE2O3-SeO2 and for RE2O3 and SeO2 in 4
- Zhang-Pre?e,Oppermann
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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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- Characterization of neodymium trichloride hydrates and neodymium hydroxychloride
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Neodymium trichloride hexahydrate (NdCl3·6H2O) was dehydrated by heating it in either air, argon, HCl or argon - HCl mixtures to germinate the intermediate species. The hexahydrate (NdCl3·6H2O) was found to deco
- Kipouros, Georges J.,Sharma, Ram A.
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- Tris-pyrazolylborate complexes of redox inactive lanthanides - The structures of [(TpMe2)2NdX] (X=Cl, NPh2, dpm, H2BEt2)
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A range of complexes of Ce and Nd have been prepared to compare the chemistry of the non-reducible [(TpMe2)2LnX] (Ln=Ce, Nd) with that reported previously for the redox-active samarium ion. The chloride [(TpMe2)2NdCl] is a useful starting material for the preparation of the seven coordinate [Nd(TpMe2)2OAr] (Ar=C6H4-4-X; X=H, But, Br, Ph, OMe, F, Me) and [Nd(TpMe2)2NPh2]. Crystal structures of [Nd(TpMe2)2Cl] and [Nd(TpMe2) 2NPh2] are isostructural with those of the analogous samarium species. The eight coordinate species [Nd(TpMe2) 2(β-dike)] (β-dike=(RC=O)2CH, R=Me, Ph; Bu t) and their cerium analogues (R=Ph, But) have also been prepared. The complexes are fluxional, the extent of this behaviour depending on the steric bulk of the substituents. The structure of [Nd(Tp Me2)2(ButCO)2CH] has been determined. Finally, in efforts to prepare a neodymium hydride, the unexpected borohydride [Nd(TpMe2)2(H2BEt2)] has been isolated serendipitously and structurally characterized.
- Galler, Jennifer L.,Goodchild, Sam,Gould, James,McDonald, Robert,Sella, Andrea
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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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- Kinetic study of neodymium oxide chlorination with gaseous chlorine
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The kinetics of the chlorination of neodymium oxide has been investigated by thermogravimetry between 312°C and 475°C, and for partial pressures of chlorine ranging from 10 kPa to 50 kPa. The starting temperature for the reaction of neodymium oxide with chlorine was determined to be about 250°C, leading to neodymium oxychloride as product. The results showed that, for temperatures below 425°C, the system is under chemical control and the formation of the oxychloride progresses through a nucleation and growth mechanism. The influence of chlorine mass transport through the bulk gas phase and through the boundary layer on the overall reaction rate was analyzed. In the absence of these two mass-transfer steps, a reaction order of 0.39 with respect to chlorine partial pressure, and an activation energy of 161 ± 4 kJ mol-1 were determined. A complete rate equation has been successfully developed.
- Bosco, Marta V.,Fouga, Gastón G.,Bohé, Ana E.
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- Thermal and spectroscopic studies on solid Ketoprofen of lighter trivalent lanthanides
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Solid-state Ln(L)3 compounds, where Ln stands for trivalent La, Ce, Pr, Nd, Sm, Eu, and L is ketoprofen have been synthesized. Thermogravimetry (TG), differential thermal analysis (DTA), differential scanning calorimetry (DSC) as well as X-ray diffraction powder (DRX) patterns, Fourier transformed infrared spectroscopy (FTIR), and other methods ofanalysis were used to study solid Ketoprofen of lighter trivalent lanth anides. The results provided information of the composition, dehydration, coordination mode, structure, thermal behavior, and thermal decomposition. The theoretical and experimental spectroscopic study suggests that the carboxylate group of ketoprofen is coordinate to metals as bidentatebond.
- Galico, D. A.,Holanda, B. B.,Perpetuo, G. L.,Schnitzler, E.,Treu-Filho, O.,Bannach, G.
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p. 371 - 380
(2012/04/23)
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- Synthesis, characterization and thermal behaviour of light trivalent lanthanides folates on solid state
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Solid state Ln2-L3 compounds, where Ln stands for light trivalent lanthanides (lanthanum to gadolinium), except promethium, and L is folate (C19H17N7O6), have been synthesized. Simultaneous thermogravimetry and differential thermal analysis (TG-DTA), differential scanning calorimetry (DSC), X-ray powder diffractometry, infrared spectroscopy (FTIR), TG coupled to FTIR, elemental analysis and complexometry were used to characterize and to study the thermal behaviour of these compounds. The results provided information concerning the stoichiometry, crystallinity, ligand's denticity, thermal stability, thermal behaviour and identification of the gaseous products evolved during the thermal decomposition of these compounds.
- Dametto, P. R.,Caires, F. J.,Ambrozini, B.,Ionashiro, M.
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p. 831 - 836
(2011/11/04)
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- Thermal studies on solid 1,4-bis(3-carboxy-3-oxo-prop-1-enyl) benzene oflighter trivalent lanthanides
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Solid-state compounds of general formula Ln2L 3·nH2O, where L represents 1,4-bis(3-carboxy-3- oxoprop-1-enyl)benzene and Ln = La, Ce, Pr, Nd, Sm, were synthesized. Complexometric titrations with EDTA, thermogravimetry (TG), differential thermal analysis (DTA), differential scanning calorimetry (DSC), X-ray powder diffractometry, elemental analysis and infrared spectroscopy have been employed to characterize and to study the thermal behavior of these compounds in dynamic air atmosphere. The results led to information about the composition, dehydration, crystallinity, and thermal decomposition of the synthesized compounds.
- Nunes, Ronaldo S.,Bannach, Gilbert,Luiz, Jose M.,Caires, Flavio J.,Carvalho, Claudio T.,Ionashiro, Massao
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p. 525 - 530
(2012/01/31)
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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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- Properties of tellurite/halide glasses of the NdCl3-TeO 2-WO3 system
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Tellurite/halide glasses of the NdCl3-TeO2-WO 3 system have been synthesized. The spectral and electrical properties of the glasses have been investigated. Data on the effect of the atmospheric moisture on the glass have b
- Safonov,Tsygankov
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p. 1740 - 1742
(2008/10/09)
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- The NdCl3-TeO2-WO3 system
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The interaction between the components in the NdCl3-TeO 2-WO3 system have been investigated using differential thermal analysis in combination with visual polythermal and X-ray powder diffraction analyses. The compositions
- Safonov
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p. 1737 - 1739
(2008/10/09)
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- A series of new polyoxoanion-based inorganic-organic hybrids: (C 6NO2H5)[(H2O)4(C 6NO2H5)Ln(CrMo6H6O 24)] · 4H2O (Ln = Ce, Pr, La and Nd) with a chiral layer structure
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Four new polyoxoanion-based hybrids with a chiral layer structure, (C 6NO2H5)[(H2O)4(C 6NO2H5)Ln(CrMo6H6O 24)] · 4H2O (Ln = Ce, 1; Pr, 2; La, 3 and Nd, 4), have been synthesized and characterized by elemental analysis, IR spectroscopy, TG analysis and single crystal X-ray diffraction. All the compounds are isostructural and crystallize in the monoclinic space group C2/c. Their crystal structures consist of two kinds of chiral layers, one left-handed and the other right-handed, each built up from the same-handed rare earth polyoxometalate helical chains, which leads to mesomeric solid state compounds. To our knowledge, this represents the first example of a 2D chiral layer framework consisting of rare earth polyoxometalate helical chains and organic bridging ligands. The magnetic properties of compounds 1, 2 and 4 have been studied by measuring their magnetic susceptibility over the temperature range of 2-300 K. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2005.
- An, Haiyan,Xiao, Dongrong,Wang, Enbo,Li, Yangguang,Xu, Lin
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p. 667 - 672
(2007/10/03)
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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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- 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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- Phase diagram of the neodymium chloride-sodium chloride system
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Differential thermal analysis was used to study the phase diagram of NdCl3-NaCl system. The peritectic reaction was found to occur at 540±7°C. The peritectic compound was confirmed to be Na3Nd5Cl18 by means of X
- Sato,Ogawa
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p. 363 - 371
(2008/10/08)
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