Fehlende Glieder bekannter Reihen: Die Oxoferrate(III) Rb8[Fe2O7], Rb6[Fe2O6] und K4[Fe2O5] / Missing Links in Known Series: The Oxoferrates(III) Rb8[Fe2O7], Rb6[Fe2O6], and K4[Fe2O5]

2005 ◽  
Vol 60 (7) ◽  
pp. 732-740 ◽  
Author(s):  
Gero Frisch ◽  
Caroline Röhr
Keyword(s):  
Single Crystal ◽  
Structure Type ◽  
Potassium Ferrate ◽  
X Ray Diffraction ◽  
Marked Contrast ◽  
Ionic Radii ◽  
Space Group ◽  
X Ray ◽  
Type Space ◽  
Alkaline Cations

The title compounds were synthesized at temperatures between 775 and 1175 K from (mostly stoichiometric) mixtures of Fe2O3, elemental rubidium or potassium (A) and their hyperoxides AO2. The structures have been determined by single crystal X-ray diffraction. The alkaline rich ferrate(III) Rb8[Fe2O7] (Cs8[Fe2O7] structure type, space group P21/c, a = 696.7, b = 1722.1, c = 692.0 pm, β = 119.40°, Z = 2, R1 = 0.0496) exhibits diferrate anions [Fe2O7]8- composed of two vertexsharing [FeIIIO4] tetrahedra with a linear Fe-O-Fe bridge and nearly ideal 3m symmetry. This is in marked contrast to the Na homologue, where the diferrate anions are decidedly angular. In the series A3[FeO3], the anions in the compounds of the light alkaline cations are chains 1∞[FeO2O2/2]3−, but similar to the isotypic K6[Fe2O6] and to Cs6[Fe2O6] the new ferrate Rb6[Fe2O6] (K6Fe2O6 structure type, space group C2/m, a=741.8(2), b=1148.7(2), c=680.08(12) pm, β =103.65(2)°, Z = 4, R1 = 0.0370) contains isolated binuclear anions [O2FeO2FeO2]6− composed of two edge sharing [FeO4] tetrahedra. The new potassium ferrate of the series A4[Fe2O5], K4[Fe2O5] (space group P21/c, a = 645.91(14), b = 593.69(13), c = 1003.0(2) pm, β = 103.124(4)°, Z = 4, R1 = 0.0355), constitutes a new structure type, but its structure is still closely related to the Na compound, which crystallizes in the isomorphous subgroup P21/n with a doubled a axis. Both compounds are phylloferrates with layers 2∞[Fe2O5]4− consisting of six-membered rings of [FeO4] tetrahedra. In contrast, Rb4[Fe2O5] contains chains of vertex and edge sharing tetrahedra, so that in both series, A3[FeO3] and A4[Fe2O5], the linkedness of the ferrate tetrahedra increases with the ionic radii of the A counterions.

Kristallstruktur von K4O(CN)2 / Crystal Structure of K4O(CN)2

1992 ◽  
Vol 47 (12) ◽  
pp. 1746-1748 ◽  
Author(s):  
Christian Hardt ◽  
Petra Vogt ◽  
Horst Sabrowsky
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Structure Type ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Type Space

Colorless K4O(CN)2 has been prepared. The compound crystallizes in the tetragonal anti-K2NiF4 structure type (space group I4/mmm) with a = 515.5(1) and c = 1606.7(3) pm, Z = 2. The structure was determined by single crystal X-ray diffraction, R = 3.35%.

AlkalineEarthMetal-Hydride-Iodide Compounds: Syntheses andCrystal Structures of Sr2H3I and Ba5H2I3.9(2)O2

2011 ◽  
Vol 66 (1) ◽  
pp. 21-26
Author(s):  
Olaf Reckeweg ◽  
Francis J. DiSalvo
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Structural Model ◽  
Structure Type ◽  
Lattice Parameters ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
New Compounds

Single crystals of Sr2H3I andBa5H2I3.9(2)O2 were obtained by reacting Sr or Ba, respectively, with dried and sublimed NH4I in a 4 : 1 molar ratio in silica-jacketed Nb ampoules for 13 h at 1200 K. The crystal structures of the new compounds have been determined by means of single-crystal X-ray diffraction. Sr2H3I crystallizes in a stuffed anti-CdI2 structure isotypic to Ba2H3Cl in the space group P3m1 (no. 164) with the lattice parameters a = 426.0(1) and c = 774.9(2) pm, while Ba5H2I3.9(2)O2 crystallizes in a new structure type in the space group Cmcm (no. 63) with the lattice parameters a = 1721.0(2), b = 1452.5(2) and c = 639.03(9) pm. The structural results for Sr2H3I are corroborated by EUTAX calculations. For the disordered compound Ba5H2I3.9(2)O2, EUTAX calculations on an approximated, ordered structural model were used to find possible insights into the disorder

The isotypic family of the diarsenates MM′As2O7 (M = Sr, Ba; M′ = Cd, Hg)

2016 ◽  
Vol 71 (5) ◽  
pp. 403-409 ◽  
Author(s):  
Matthias Weil
Keyword(s):  
Aqueous Solutions ◽  
Single Crystal ◽  
Metal Oxides ◽  
Structure Type ◽  
Hydrothermal Conditions ◽  
Space Group ◽  
X Ray ◽  
Type Space ◽  
Autogenous Pressure

AbstractThe diarsenates MM′As2O7 (M = Sr, Ba; M′ = Cd, Hg) were prepared under hydrothermal conditions (~200 °C, autogenous pressure), starting from As2O5 and the corresponding metal oxides or precursor compounds thereof in aqueous solutions. Structure analyses on the basis of single crystal X-ray data revealed the four structures to be isotypic. They are the first diarsenates to crystallize in the triclinic BaZnP2O7 structure type (space group P1̅, Z = 2, a ≈ 5.8 Å, b ≈ 7.3 Å, c ≈ 7.6 Å, α ≈ 101°, β ≈ 91°, γ ≈ 98°). All related MM′As2O7 diarsenates reported so far (M = Sr, Ba, Pb; M′ = Mg, Co, Cu, Zn) crystallize in the monoclinic α-Ca2P2O7 structure type (P21/n, Z = 4). Hence, the size of the divalent M′ cation determines which of the two structure types is adopted.

scholarly journals Two new glaserite-type orthovanadates: Rb2KDy(VO4)2 and Cs1.52K1.48Gd(VO4)2

2019 ◽  
Vol 75 (7) ◽  
pp. 1041-1045
Author(s):  
Lotfi Rghioui ◽  
Lahcen El Ammari ◽  
Abderrazzak Assani ◽  
Mohamed Saadi
Keyword(s):  
Single Crystal ◽  
Crystal Structures ◽  
Diffraction Data ◽  
Structure Type ◽  
X Ray Diffraction ◽  
Flux Method ◽  
Space Group ◽  
X Ray ◽  
Oxygen Atoms ◽  
Reactive Flux

The crystal structures of dirubidium potassium dysprosium bis(vanadate), Rb2KDy(VO4)2, and caesium potassium gadolinium bis(vanadate), Cs1.52K1.48Gd(VO4)2, were solved from single-crystal X-ray diffraction data. Both compounds, synthesized by the reactive flux method, crystallize in the space group P\overline{3}m1 with the glaserite structure type. VO4 tetrahedra are linked to DyO6 or GdO6 octahedra by common vertices to form sheets stacking along the c axis. The large twelve-coordinate Cs+ or Rb+ cations are sandwiched between these layers in tunnels along the a and b axes, while the K+ cations, surrounded by ten oxygen atoms, are localized in cavities.

scholarly journals Single-crystal investigation of the compound SmNi5.2Mn6.8

2020 ◽  
Vol 75 (3) ◽  
pp. 303-307
Author(s):  
Bohdana Belan ◽  
Dorota Kowalska ◽  
Mykola Manyako ◽  
Mariya Dzevenko ◽  
Yaroslav Kalychak
Keyword(s):  
Crystal Structure ◽  
Intermetallic Compound ◽  
Single Crystal ◽  
Diffraction Data ◽  
Structure Type ◽  
Tetragonal Structure ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Arc Melting

AbstractThe intermetallic compound SmNi5.2Mn6.8 was synthesized by arc-melting and its crystal structure has been determined using single-crystal X-ray diffraction data. The compound adopts the tetragonal structure type ThMn12: space group I4/mmm, Pearson code tI26, Z = 2; a = 8.6528(3), c = 4.8635(3) Å; R1 = 0.0175, wR2 = 0.0372, 171 F2 values, 17 refined variables. The two crystallographic positions 8f and 8j in the structure of SmNi5.2Mn6.8 are occupied by a mixture of Mn and Ni atoms.

Single Crystal Investigation and Physical Properties of the Binary Compound CeB4

2007 ◽  
Vol 62 (7) ◽  
pp. 896-900 ◽  
Author(s):  
Volodymyr Babizhetskyy ◽  
Arndt Simon ◽  
Kurt Hiebl
Keyword(s):  
Electrical Resistivity ◽  
Physical Properties ◽  
Single Crystal ◽  
Structure Type ◽  
Binary Compound ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Resistivity Measurements ◽  
Cerium Atom

Abstract The structure of CeB4 has been determined by single crystal X-ray diffraction. The compound crystallizes in the ThB4 structure type (space group P4/mbm, a = 7.2034(8), c = 4.1006(5) Å; 270 reflections with Fo ≥ 4σ (Fo), R1 = 0.023, wR2 = 0.052). The results of the magnetic and electrical resistivity measurements indicate a strong f-d hybridization of the 4 f electrons of the cerium atom

Trigonal structures of ABe2BO3F2 (A = Rb, Cs, Tl) crystals

2009 ◽  
Vol 65 (4) ◽  
pp. 445-449 ◽  
Author(s):  
Colin D. McMillen ◽  
Jia Hu ◽  
Donald VanDerveer ◽  
Joseph W. Kolis
Keyword(s):  
Single Crystal ◽  
Crystal Structures ◽  
Structure Type ◽  
Structural Features ◽  
X Ray Diffraction ◽  
Higher Symmetry ◽  
Space Group ◽  
X Ray ◽  
Trigonal Structure

Several interesting fluoroberyllium borates were synthesized hydrothermally and characterized by single-crystal X-ray diffraction. The crystal structures of RbBe2BO3F2 (RBBF; rubidium fluoroberyllium borate) and CsBe2BO3F2 (CBBF; caesium fluoroberyllium borate), previously determined in the space group C2, were reinvestigated for higher symmetry and found to have more suitable solutions in the space group R32. TlBe2BO3F2 (TBBF; thallium fluoroberyllium borate) was synthesized as a novel compound also having this trigonal structure type. Details of the space-group determination and unique structural features are discussed. These crystal structures were compared with that of KBe2BO3F2, revealing interesting structural trends within this family of compounds that are also discussed. A crystallographic explanation of the physical morphology is postulated.

Crystal structure of an inclusion complex between chiral monoaza-15-crown-5 and S(–)-1-phenyl-ethyl ammonium percholorate

2003 ◽  
Vol 218 (5) ◽  
Author(s):  
Süheyla Özbey ◽  
F. B. Kaynak ◽  
M. Toğrul ◽  
N. Demirel ◽  
H. Hoşgören
Keyword(s):  
Crystal Structure ◽  
Inclusion Complex ◽  
Single Crystal ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
New Type

AbstractA new type of inclusion complex, S(–)-1 phenyl ethyl ammonium percholorate complex of R-(–)-2-ethyl - N - benzyl - 4, 7, 10, 13 - tetraoxa -1- azacyclopentadecane, has been prepared and studied by NMR, IR and single crystal X-ray diffraction techniques. The compound crystallizes in space group

Single-crystal investigation of Ce5AgxGe4−x (x = 0.1−1.08) with Sm5Ge4 type

2020 ◽  
Vol 75 (8) ◽  
pp. 765-768
Author(s):  
Bohdana Belan ◽  
Dorota Kowalska ◽  
Mariya Dzevenko ◽  
Mykola Manyako ◽  
Roman Gladyshevskii
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Diffraction Data ◽  
Binary Compound ◽  
Lattice Parameters ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray

AbstractThe crystal structure of the phase Ce5AgxGe4−x (x = 0.1−1.08) has been determined using single-crystal X-ray diffraction data for Ce5Ag0.1Ge3.9. This phase is isotypic with Sm5Ge4: space group Pnma (No. 62), Pearson code oP36, Z = 4, a = 7.9632(2), b = 15.2693(5), c = 8.0803(2) Å; R1 = 0.0261, wR2 = 0.0460, 1428 F2 values and 48 variables. The two crystallographic positions 8d and 4c show Ge/Ag mixing, leading to a slight increase in the lattice parameters as compared to those of the pure binary compound Ce5Ge4.

The wulfenite—stolzite series: centric or acentric structures?

2008 ◽  
Vol 72 (4) ◽  
pp. 987-990 ◽  
Author(s):  
L. Secco ◽  
F. Nestola ◽  
A. Dal Negro
Keyword(s):  
Single Crystal ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
End Members ◽  
Symmetry Change

AbstractThree natural crystals of the wulfenite (PbMoO4)—stolzite (PbWO4) series were investigated by single-crystal X-ray diffraction. The results indicate that the symmetry is I41/a from nearly pure wulfenite to intermediate compositions, in contrast to previous work which claimed a symmetry change to 74 symmetry (acentric) for intermediate compositions compared with I41/a (centric space group) for the end-members. The results reported here show that the reflections violating I41/a symmetry observed in this work and in a previous study are related primarily to λ/2 effects, even if Renninger effects are not excluded. Consequently, we find that the I41/a symmetry is retained throughout the wulfenite— stolzite.

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