Polar potassium rare earth nitrates K2[RE(NO3)5(H2O)2] (RE = La, Ce, Pr and Nd). I. Crystal growth and crystal structures

2000 ◽  
Vol 33 (2) ◽  
pp. 372-379 ◽  
Author(s):  
P. Held ◽  
H. Hellwig ◽  
S. Rühle ◽  
L. Bohatý
Keyword(s):  
Rare Earth ◽  
Optical Quality ◽  
Rare Earth Ions ◽  
Water Molecules ◽  
Hard Sphere Model ◽  
Stoichiometric Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Rare Earth Nitrates ◽  
Evaporation Technique

Using a standard evaporation technique at 311 K, large single crystals of the polar orthorhombic potassium rare earth nitrates K2RE(NO3)5.2H2O, where RE = La, Ce, Pr or Nd, of optical quality and dimensions up to 5 × 5 × 4 cm, were grown from aqueous solutions containing a stoichiometric ratio of potassium and rare earth ions (K:RE = 2:1) and a surplus of nitric acid. Detailed structural and crystal chemical analyses of all four isomorphic compounds based on single-crystal X-ray diffraction data were carried out [space groupFdd2;Z= 8; La compound:a= 11.2814 (6),b= 21.480 (1),c= 12.2589 (4) Å,R= 0.94%; Ce compound:a= 11.263 (3),b= 21.404 (3),c= 12.230 (4) Å,R= 1.92%; Pr compound:a= 11.213 (2),b= 21.392 (4),c= 12.204 (2) Å,R= 1.58%; Nd compound:a= 11.197 (1),b= 21.378 (1),c= 12.195 (1) Å,R= 1.55%]. The main structural feature is the diaquapentanitratolanthanide(III) group, [RE(NO3)5(H2O)2]2−, as stated earlier by Eriksson, Larsson, Niinistö & Valkonen [Acta Chem. Scand. Ser. A, (1980),34, 567–572] for the La compound. The rare earth atoms are surrounded by 12 O atoms, two of which belong to water molecules, the remaining ten belonging to five bidentate nitrate groups. The coordination polyhedron [REO12] is a distorted icosahedron; its geometry is discussed using a simple hard-sphere model.

Synthesis, Fluorescence Properties of 2-Acetyl-2'-Chloroacetanilide with Rare Earth Nitrates Complexes

2011 ◽  
Vol 219-220 ◽  
pp. 574-577
Author(s):  
Xi Shi Tai ◽  
Lin Tong Wang
Keyword(s):  
Rare Earth ◽  
Rare Earth Ions ◽  
Fluorescence Properties ◽  
Water Molecules ◽  
Single Crystal Diffraction ◽  
X Ray ◽  
Rare Earth Nitrates ◽  
Ft Ir ◽  
Coordinated Water ◽  
The Eu

The reaction of 2-acetyl-2'-chloroacetanilide (L) with rare earth nitrates in CH3CH2OH followed by recrystallization in CH3CH2OH gave rise to colorless block crystals materials. The complexes and ligand were analyzed by FAB, elemental analysis(C, H, N), FT-IR spectra, TG-DTA, molar conductivity and X-ray single crystal diffraction. The fluorescence properties of ligand and the Eu (Ⅲ) complex also have been investigated. The results of crystal structure and spectral data show that the rare earth ions coordinated with oxygen and nitrogen atoms of the ligand, the nitrate and coordinated water molecules. The Eu (Ⅲ) complex material shows characteristic red emissions.

Synthesis, Morphology Control and Luminescent Properties of Rare Earth Ion-Doped CaWO4 Microstructures

2016 ◽  
Vol 16 (4) ◽  
pp. 4029-4034 ◽  
Author(s):  
Chunxia Liu ◽  
Lixia Yang ◽  
Dan Yue ◽  
Mengnan Wang ◽  
Lin Jin ◽  
...  
Keyword(s):  
Rare Earth ◽  
Uv Light ◽  
Luminescent Properties ◽  
Average Diameter ◽  
Rare Earth Ions ◽  
X Ray Diffraction ◽  
Hydrothermal Route ◽  
Rare Earth Ion ◽  
X Ray ◽  
Facile Hydrothermal Route

Rare earth ions (Tb3+, Eu3+) doped CaWO4 microstructures were synthesized by a facile hydrothermal route without using any templates and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence (PL) spectrum. The results indicate that the asprepared samples are well crystallized with scheelite structure of CaWO4, and the average diameter of the microstructures is 2∼4 μm. The morphology of CaWO4:Eu3+ microstructures can be controllably changed from microspheres to microflowers through altering the doping concentration of Eu3+ from 3% to 35%, and the microflowers are constructed by a number of CaWO4:Eu3+ nanoflakes. Under the excitation of UV light, the emission spectrum of CaWO4:Eu3+ is composed of the characteristics emission of Eu3+ 5D0-7FJ (J = 1, 2, 3, 4) transitions, and that of CaWO4:Tb3+ is composed of Tb3+ 5D4-7FJ (J = 6, 5, 4, 3) transitions. Both of the optimal doping concentrations of Tb3+ and Eu3+ in CaWO4 microstructures are about 5%.

Effects of Acidity on Nitrogen-Heterocyclic Compounds with Rare Earth Coordination and the Structure of Protonated Phenanthroline

2011 ◽  
Vol 233-235 ◽  
pp. 2808-2811
Author(s):  
Huan Huan Li ◽  
Hai Bin Chu ◽  
Ying Nan Chen ◽  
Xiao Tao Fu ◽  
Hui Juan Sun ◽  
...  
Keyword(s):  
Rare Earth ◽  
Heterocyclic Compounds ◽  
Crystal Structure Analysis ◽  
Rare Earth Ions ◽  
Molecular Formula ◽  
X Ray Diffraction ◽  
Triclinic Space Group ◽  
X Ray ◽  
Rare Earth Coordination ◽  
Single Crystal Structure Analysis

2,3-bis(2-pyridyl)-5,6-dihydropyrazine and a protonated phenanthroline (Phen) have been synthesized and the structure of protonated Phen is established by X-ray diffraction single crystal structure analysis. The coordination reactions of Phen, 2,2'- bipyridine and 2,3-bis(2-pyridyl)-5,6-dihydropyrazine with rare earth ions in low pH have been studied. The results show that 2,3-bis(2-pyridyl)-5,6-dihydropyrazine is hydrolyzed to be 2,2’-pyridil and protonated ethylenediamine. Meanwhile, Phen combines with proton, which results that nitrogen atoms can not coordinate with rare earth ions. The molecular formula of protonated Phen is C12H8N2HCl·H2O. It crystallizes in the triclinic space group P -1 (2), with a = 7.1212(14) Å, b = 7.2786(15) Å, c = 20.817(4) Å, α = 90.00º, β = 96.69(3) º, γ = 90.00 º, V = 1071.65(379) Å3, Z = 4.

Structural Systematics of Rare Earth Complexes. XIII (‘Maximally’) Hydrated (Heavy) Rare Earth Nitrates

1999 ◽  
Vol 52 (6) ◽  
pp. 497 ◽  
Author(s):  
David L. Kepert ◽  
Peter C. Junk ◽  
Brian W. Skelton ◽  
Allan H. White
Keyword(s):  
Rare Earth ◽  
The Other ◽  
Water Molecules ◽  
Bidentate Ligands ◽  
X Ray ◽  
Rare Earth Nitrates ◽  
Triclinic Phase ◽  
Cell Dimensions ◽  
Structure Determinations ◽  
Coordinated Water

Room-temperature single-crystal X-ray structure determinations are known for a number of ‘maximally hydrated" nitrates of, in particular, the lighter lanthanoid elements; in all cases, all nitrates coordinate as O,O′-bidentate ligands so that the series may be represented at the outset as Ln(O2NO)3.x H2O. Two distinct triclinic P 1 hexahydrate phases of similar cell dimensions are recognized, the most distinctive distinguishing feature being that in the La, Ce phase the 11-coordinate Ln is surrounded by three O,O′-bidentate nitrate and five O-unidentate water molecule ligands; the domain of the other, with four coordinated water molecules, extends from Ln = Pr to Ln = Dy (inclusive of Y). At local ambience, we have crystallized heavier members of the series as pentahydrates, isomorphous with the previously characterized Ln = Eu example, also containing a molecule of the form [Ln(O2NO)3(OH2)4] (with a molecule of water of crystallization), but a different stereoisomer to that found in the Ln = Pr(-)Dy array. Structure determinations are recorded for Ln = Dy, Er, Yb, conventional R on |F| 0·042, 0·034, 0·029 for No = 3858, 3980, 3935 independent ‘observed’ (I > 3σ(I)) diffractometer reflections. For Ln = Lu a new tetrahydrate phase is described, monoclinic P21/n, a 7·379(7), b 10·364(5), c 14·26(1) Å, β 96·09(7)°, Z = 4, R 0·048 for No 2324, together with a new triclinic P 1 trihydrate, a 12·591(4), b 12·144(3), c 7·355(2) Å, α 80·22(2), β 77·68(3), γ 62·30(2)°, Z = 4, R 0·051 for No 4552. In both of the latter, Lu is nine-coordinate, with three bidentate nitrate groups and three coordinated water molecules; remarkably, the two independent molecules of the asymmetric unit in the triclinic phase are distinct isomers, one having the water molecules fac, derivative of the 10-coordinate array of the Pr(-)Yb series with quasi-3 symmetry, while the other, like that in the monoclinic phase, is mer.

GROWTH AND CHARACTERIZATION OF NONLINEAR OPTICAL PARA-NITROANILINE (pNA) SINGLE CRYSTALS

2007 ◽  
Vol 21 (29) ◽  
pp. 2025-2032 ◽  
Author(s):  
T. BARANIRAJ ◽  
P. PHILOMINATHAN ◽  
N. VIJAYAN
Keyword(s):  
Single Crystals ◽  
Nonlinear Optical ◽  
Optical Quality ◽  
X Ray Diffraction ◽  
X Ray ◽  
Evaporation Technique ◽  
Optical Behavior ◽  
Good Optical Quality ◽  
Thermal Stability Of

Single crystals of para Nitroaniline ( pNA ), an organic nonlinear optical (NLO) material, have been grown by slow solvent evaporation technique at room temperature. Good optical quality single crystals with dimensions of up to 10 × 11 × 3 mm 3 have been grown by adopting the above technique, and good quality single crystals were obtained. The grown single crystals were subjected to different characterization analyses. The lattice dimensions have been determined from the powder X-ray diffraction analysis. Its functional groups and optical behavior have been identified from the FTIR and UV-Vis. analyses respectively. The thermal stability of the crystal has been analyzed by thermogravimetric (TG) and differential thermal (DT) analyses respectively.

scholarly journals Single-Crystal Growth of Metallic Rare-Earth Tetraborides by the Floating-Zone Technique

Crystals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 211 ◽  
Author(s):  
Daniel Brunt ◽  
Monica Ciomaga Hatnean ◽  
Oleg A. Petrenko ◽  
Martin R. Lees ◽  
Geetha Balakrishnan
Keyword(s):  
Rare Earth ◽  
Single Crystal Growth ◽  
Rare Earth Ions ◽  
Floating Zone ◽  
X Ray Diffraction ◽  
Zone Method ◽  
X Ray ◽  
Resistivity Measurements ◽  
Field Dependent ◽  
The Rare Earth

The rare-earth tetraborides are exceptional in that the rare-earth ions are topologically equivalent to the frustrated Shastry-Sutherland lattice. In this paper, we report the growth of large single crystals of RB 4 (where R = Nd, Gd → Tm, and Y) by the floating-zone method, using a high-power xenon arc-lamp furnace. The crystal boules have been characterized and tested for their quality using X-ray diffraction techniques and temperature- and field-dependent magnetization and AC resistivity measurements.

Magnetic properties of (Sr1.85Ln0.15)FeMoO6 with Ln = Sr, La, Ce, Pr, Nd, Sm and Eu

2011 ◽  
Vol 239-242 ◽  
pp. 3109-3112 ◽  
Author(s):  
Qin Zhang ◽  
Qing Wang ◽  
Zhen Cui Sun ◽  
Ke Yan Wang
Keyword(s):  
Magnetic Properties ◽  
Rare Earth ◽  
Ionic Radius ◽  
Single Phase ◽  
Magnetic Measurements ◽  
Rare Earth Ions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Rare Earth Doped ◽  
The Eu

Rare-earth-doped compounds (Sr1.85Ln0.15)FeMoO6(Ln=Sr, La, Ce, Pr, Nd, Sm and Eu) have been prepared by solid-state reaction. Crystal structure and magnetic properties were investigated by means of X-ray diffraction and magnetic measurements. All the samples are single phase and belong to the I4/m space group. Due to the competing contributions of electron doping and steric effects, the unit-cell volume of the doped compounds changes slightly and does not vary systematically with the ionic radius of the rare-earth ions. The temperature dependence of the magnetization of (Sr1.85Ln0.15)FeMoO6indicates that the Curie temperature of the doped compounds has increased upon doping, except for the Eu-doped compound.

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