Cation ordering in the double tungstate LiFe(WO4)2

2012 ◽  
Vol 68 (2) ◽  
pp. i7-i8 ◽  
Author(s):  
Marjorie Albino ◽  
Stanislav Pechev ◽  
Philippe Veber ◽  
Matias Velazquez ◽  
Michael Josse
Keyword(s):  
High Temperature ◽  
Cation Ordering ◽  
Monoclinic Space Group ◽  
High Temperature Solution ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
Double Tungstate ◽  
Growth Method ◽  
Temperature Solution ◽  
Expected Values

Single crystals of lithium iron tungstate, LiFe(WO4)2, were obtained using a high-temperature solution growth method. The analysis was conducted using the monoclinic space groupC2/c, with β = 90.597 (2)°, givingR1 = 0.0177. The Li and Fe atoms lie on twofold axes. The structure can also be refined using the orthorhombic space groupCmcm, giving slightly higher residuals. The experimental value of β and the residuals mitigate in favour of the monoclinic description of the structure. Calculated bond-valence sums for the present results are closer to expected values than those obtained using the results of a previously reported analysis of this structure.

Synthesis, crystal structure and luminescence properties of a new samarium borate phosphate, CsNa2Sm2(BO3)(PO4)2

2020 ◽  
Vol 76 (12) ◽  
pp. 1068-1075
Author(s):  
Dan Zhao ◽  
Lin-Ying Shi ◽  
Rui-Juan Zhang ◽  
Ya-Li Xue
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
Three Dimensional ◽  
High Temperature Solution ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Temperature Solution ◽  
Light Excitation ◽  
Total Structure

A new caesium sodium samarium borate phosphate, CsNa2Sm2(BO3)(PO4)2, has been obtained successfully by the high-temperature solution growth (HTSG) method and single-crystal X-ray diffraction analysis reveals that it crystallizes in the orthorhombic space group Cmcm. The structure contains BO3, PO4, NaO7 and SmO7 polyhedra which are interconnected via corner- or edge-sharing O atoms to form a three-dimensional [Na2Sm2(BO3)(PO4)2]∞ network. This network delimits large cavities where large Cs+ cations reside to form the total structure. Under 402 nm light excitation, CsNa2Sm2(BO3)(PO4)2 exhibits three emission bands due to the 4f→4f transitions of Sm3+. Furthermore, we introduced Gd3+ into Sm3+ sites to optimize the Sm3+ concentration and improve the luminescence intensity. The optimal concentration is Gd/Sm = 98/2. The luminescent lifetime of a series of CsNa2Gd2(1–x)Sm2x (BO3)(PO4)2 phosphors shows a gradual degradation of lifetime from 2.196 to 0.872 ms for x = 0.01–0.10. The Commission Internationale de l'Eclairage (CIE) 1931 calculation reveals that CsNa2Gd1.96Sm0.04(BO3)(PO4)2 can emit orange light under 402 nm excitation.

RbPb8O4Cl9: First Alkali Metal Lead Oxyhalide with Distorted [PbO3Cl3] and [PbOCl5] Mixed-Anion Groups

2021 ◽  
Author(s):  
Zhongxu Fan ◽  
Chen Bai ◽  
Hongsheng Shi ◽  
Min Zhang ◽  
Bei Zhang ◽  
...  
Keyword(s):  
Heavy Metal ◽  
High Temperature ◽  
Alkali Metal ◽  
Solution Method ◽  
Three Dimensional ◽  
High Temperature Solution ◽  
Space Group ◽  
Centrosymmetric Space Group ◽  
Temperature Solution ◽  
3D Framework

A new heavy metal oxychloride, RbPb8O4Cl9, has been synthesized by high-temperature solution method. The compound crystallizes in the centrosymmetric space group P4/n (no. 85) and exhibits a three-dimensional (3D) framework...

Na2La2B10O19: A New Lanthanum Sodium Borate with Infinite 2D Layer (_∞﷩2﷩[B_10 O_19 ]^(8-)and Moderate Birefringence

2021 ◽  
Author(s):  
Chengfa Wu ◽  
Junwei Feng ◽  
Feng Yu
Keyword(s):  
Rare Earth ◽  
High Temperature ◽  
Sodium Borate ◽  
Two Dimensional ◽  
High Temperature Solution ◽  
Spontaneous Crystallization ◽  
Space Group ◽  
Layer 2 ◽  
Rare Earth Borate ◽  
Temperature Solution

A new rare earth borate Na2La2B10O19 was successfully synthesized by spontaneous crystallization in high temperature solution. It crystallizes in the centrosymmetric (CS) space group C2/c with an infinite two-dimensional (2D)...

Two reversible enantiotropic phase transitions in a pentacoordinate silicon complex with anO,N,O′-tridentate valinate ligand

2015 ◽  
Vol 71 (6) ◽  
pp. 511-516 ◽  
Author(s):  
Anke Schwarzer ◽  
Sabine Fels ◽  
Uwe Böhme
Keyword(s):  
Phase Transitions ◽  
High Temperature ◽  
Low Temperature ◽  
Monoclinic Space Group ◽  
Isopropyl Group ◽  
Orthorhombic Space Group ◽  
Chiral Compound ◽  
Space Group ◽  
Temperature Form ◽  
High Temperature Form

Dimethyl[N-(4-oxidopent-3-en-2-ylidene)valinato-κ3O,N,O′]silicon(IV), C12H21NO3Si, (II), crystallizes in the orthorhombic space groupP212121. The chiral compound undergoes two sharp enantiotropic phase transitions upon cooling. The first transformation occurs at 163 K to yield a unit cell with one axis having double length. This intermediate-temperature form has the monoclinic space groupP21. The second transition takes place at 142 K and converts the single crystal into the low-temperature form in the orthorhombic space groupP212121. This transition proceeds under tripling of theaaxis of the high-temperature form. Both phase transitions are fully reversible and correspond to order–disorder transitions of the isopropyl group of the valine unit in the ligand backbone. The phase transitions presented here raise questions, since they do not fit into the rules of group–subgroup relationships.

Strukturuntersuchungen an Diaryldichalkogeniden: Die Molekülstrukturen von [2,4,6-(CF3)3C6H2S]2,[2,4,6-Me3C6H2Te]2 und [2-Me2N-4,6-(CF3)2C6H2Te]2 / Structural Investigations of Diaryl Dichalcogenides: The Molecular Structures of [2,4,6-(CF3)3C6H2S]2, [2,4,6-Me3C6H2Te]2 and [2-Me2N-4,6-(CF3)2C6H2Te]2

1992 ◽  
Vol 47 (3) ◽  
pp. 305-309 ◽  
Author(s):  
Anja Edelmann ◽  
Sally Brooker ◽  
Norbert Bertel ◽  
Mathias Noltemeyer ◽  
Herbert W. Roesky ◽  
...  
Keyword(s):  
Molecular Structures ◽  
Monoclinic Space Group ◽  
Crystal Data ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Structural Investigations ◽  
Space Group ◽  
X Ray

Abstract The Molecular Structures of [2,4,6-(CF3)3C6H2S]2 (1) [2,4,6-Me3C6H2Te]2 and [2-Me2N-4,6-(CF3)2C6H2Te]2 (3) have been determined by X-ray diffraction. Crystal data: 1: orthorhombic, space group P212121, Z = 4, a = 822.3(2), b = 1029.2(2), c = 2526.6(5) pm (2343 observed independent reflexions, R = 0.042); 2: orthorhombic, space group Iba 2, Z = 8, a = 1546.5(2), b = 1578.4(2), c = 1483.9(1) pm (2051 observed independent reflexions, R = 0.030); 3: monoclinic, space group P 21/c, Z = 4, a = 1118.7(1), b = 1536.5(2), c = 1492.6(2) pm, β = 98.97(1)° (3033 observed independent reflexions, R = 0.025).

Two lithium tricyanomethanide compounds: syntheses and single-crystal structure determination of LiK[C(CN)3]2 and Li[C(CN)3]·½ (H3C)2CO

2015 ◽  
Vol 70 (3) ◽  
pp. 191-196 ◽  
Author(s):  
Olaf Reckeweg ◽  
Francis J. DiSalvo
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Single Crystals ◽  
Structure Determination ◽  
Monoclinic Space Group ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
Cell Parameters ◽  
New Compounds

AbstractThe new compounds LiK[C(CN)3]2 and Li[C(CN)3]·½ (H3C)2CO were synthesized and their crystal structures were determined. Li[C(CN)3]·½ (H3C)2CO crystallizes in the orthorhombic space group Ima2 (no. 46) with the cell parameters a=794.97(14), b=1165.1(2) and c=1485.4(3) pm, while LiK[C(CN)3]2 adopts the monoclinic space group P21/c (no. 14) with the cell parameters a=1265.7(2), b=1068.0(2) and c=778.36(12) pm and the angle β=95.775(7)°. Single crystals of K[C(CN)3] were also acquired, and the crystal structure was refined more precisely than before corroborating earlier results.

Gemischte Alkalimetall-Oxidosulfidomolybdate A2[MoOxS4– x] (x = 1, 2, 3; A = K, Rb, Cs, NH4). Synthesen, Kristallstrukturen und Eigenschaften / Mixed Alkali Oxidosulfidomolybdates A2[MoOxS4−x] (x = 1, 2, 3; A = K, Rb, Cs, NH4).Synthesis, Crystal Structure and Properties

2012 ◽  
Vol 67 (2) ◽  
pp. 127-22
Author(s):  
Anna J. Lehner ◽  
Korina Kraut ◽  
Caroline Röhr
Keyword(s):  
Bathochromic Shift ◽  
Structure Type ◽  
Structure Theory ◽  
Monoclinic Space Group ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
Coordination Numbers ◽  
Preparation Conditions ◽  
Vis Spectroscopy ◽  
Type Orthorhombic

Mixed sulfido/oxidomolybdate anions [MoOxS4−x]2− (x = 1, 2, 3) have been prepared by passing H2S gas through a solution of oxidomolybdates. The alkali salts of K+, Rb+, Cs+, and NH+4 precipitate as crystalline salts from these solutions depending on the pH, the polarity of the solvent, the educt concentrations and the temperature. Their structures have been determined by means of X-ray single-crystal diffraction data. All trisulfidomolybdates A2[MoOS3] (A = NH4/K/Rb/Cs) are isotypic with the tetrasulfido salts, exhibiting the β -K2[SO4] type (orthorhombic, space group Pnma, Z = 4; for A = Rb: a = 940.62(4), b = 713.32(4), c = 1164.56(5) pm, R1 = 0.0281). In contrast, the disulfidomolybdates exhibit a rich crystal chemistry, forming three different structure types depending on the preparation conditions and the size of the A cation: All four cations form salts crystallizing with the (NH4)2[WO2S2] structure type (monoclinic, space group C2/c, Z = 4, for A = Rb: a = 1144.32(11), b = 732.60(4), c = 978.99(10) pm, β = 120.324(7)°, R1 = 0.0274). For the three alkali metal cations a second polymorph with a new structure type (monoclinic, space group P21/c, Z = 4) is observed in addition (for A = Rb: a = 674.83(2), b = 852.98(3), c = 1383.10(9) pm, β = 115.19(1)°, R1 = 0.0216). The cesium salt also crystallizes with a third modification of another new structure type (orthorhombic, space group Pbcn, Z = 4, a = 915.30(6), b = 777.27(7), c = 1120.02(7) pm, R1 = 0.0350). Only for K, an anhydrous monosulfidomolybdate could be obtained (K2[MoO4] structure type, monoclinic, space group C2/m, Z = 4, a = 1288.7(3), b = 615.7(2), c = 762.2(1) pm, β = 109.59(1)°, R1 = 0.0736). The intramolecular chemical bonding in the molybdate anions is discussed and compared with the respective vanadates. Hereby aspects like bond lengths, bond strengths and force constants derived from Raman spectroscopy, are taken into account. Especially for the polymorphic disulfido salts, in-depth analyses of the local coordination numbers and the packing of the ions are presented. The gradual bathochromic shift of the crystal color with increasing S content and increasing size of the counter cations A and molar volumes (for the polymorphic forms), respectively, is in accordance with the increase of the experimental (UV/Vis spectroscopy) and calculated (FP-LAPW band structure theory) band gaps.

High temperature solution growth of perovskite Pb2CoWO6 single crystals

1991 ◽  
Vol 112 (1) ◽  
pp. 71-83 ◽  
Author(s):  
B.N. Sun ◽  
R. Boutellier ◽  
Ph. Sciau ◽  
E. Burkhardt ◽  
V. Rodriguez ◽  
...  
Keyword(s):  
High Temperature ◽  
Single Crystals ◽  
Solution Growth ◽  
High Temperature Solution ◽  
Temperature Solution

scholarly journals Growth and Characterization of Centimeter-Sized Ba2LaFeNb4O15Crystals from High-Temperature Solution under a Controlled Atmosphere

2013 ◽  
Vol 2013 (15) ◽  
pp. 2817-2825 ◽  
Author(s):  
Marjorie Albino ◽  
Philippe Veber ◽  
Elias Castel ◽  
Matias Velázquez ◽  
Kurt Schenk ◽  
...  
Keyword(s):  
High Temperature ◽  
Controlled Atmosphere ◽  
High Temperature Solution ◽  
Temperature Solution
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