Die Kristallstruktur von α-ΚΖnΡΟ4 / The Crystal Structure of α-KZnPO4

1992 ◽  
Vol 47 (9) ◽  
pp. 1249-1254 ◽  
Author(s):  
Martina Andratschke ◽  
Klaus-Jürgen Range ◽  
Heinz Haase ◽  
Ulrich Klement
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Low Temperature ◽  
Single Crystals ◽  
Potassium Ions ◽  
Space Group ◽  
Temperature Modification ◽  
Type Apparatus

Single crystals of a-KZnPO4, the low-temperature modification of potassium zinc orthophosphate, were obtained from KZnPO4 powder by high pressure experiments in a modified Belt-type apparatus. The crystals are hexagonal, space group P 63, with a = 18.155(2), c = 8.504(1) Å, c/a = 0.4684 and Z = 24. The crystal structure, refined from diffractometer data to R = 0.077, Rw = 0.068, comprises an ordered network of ZnO4 and PO4 tetrahedra with rings of six tetrahedra vertical to the c-axis. The potassium ions are located in cavities formed by the rings.

scholarly journals Die Kristallstruktur von TIZnPO4 und TIZnAsO4 / The Crystal Structure of TIZnPO4 and TIZnAsO4

1994 ◽  
Vol 49 (9) ◽  
pp. 1282-1288 ◽  
Author(s):  
Martina Andratschke ◽  
Klaus-Jürgen Range ◽  
Claudia Weigl ◽  
Ulrike Schießl ◽  
Franz Rau
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Single Crystals ◽  
Structure Type ◽  
Monoclinic System ◽  
Space Group ◽  
High Pressure Synthesis ◽  
Pressure Synthesis ◽  
Derivatives Of ◽  
Type Apparatus

Single crystals of the title com pounds were obtained by high pressure synthesis in a modified Belt type apparatus. The compounds crystallize in the monoclinic system (space group P21) with a = 8.732(2), b = 5.468(1), c = 8.841(2) Å, β = 90.61(2)° for TlZnPO4 and a = 8.921(3), b = 5.631(1), c = 8.958(3) Å, β = 91.03(2)° for TlZnAsO4, Z = 4. The structures were refined from diffractom eter data to R = 0.072, Rw = 0.050 for 3700 (TlZnPO4) and to R = 0.093, Rw = 0.067 for 3943 (TlZnAsO4) independent absorption corrected reflections. The compounds are isotypic and belong to the “stuffed derivatives" of the Icmm structure type with a (ZnXO4)- network of alternating corner linked ZnO4 and XO4 tetrahedra (X = P, As) forming channels of six-membered rings in the direction of the a axis. These cavities contain two crystallographically independent Tl cations in an irregular coordination by eight nearest oxygen atoms

Hochdrucksynthese und Kristallstruktur von Kalium- und Rubidiumdiwolframat(VI), K2W2O7 und Rb2W2O7 / High-Pressure Synthesis and Crystal Structure of Potassium and Rubidium Ditungstate(VI), K2W2O7 und Rb2W2O7

1990 ◽  
Vol 45 (2) ◽  
pp. 107-110 ◽  
Author(s):  
Klaus-Jürgen Range ◽  
Wilhelm Hegenbart ◽  
Anton M. Heyns ◽  
Franz Rau ◽  
Ulrich Klement
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Single Crystals ◽  
High Pressures ◽  
Monoclinic Space Group ◽  
Potassium Ions ◽  
Synthesis And Crystal Structure ◽  
Space Group ◽  
High Pressure Synthesis ◽  
Pressure Synthesis

Potassium tungstate, K2WO4, decomposes at high pressures to give K2W2O7 and other products. Single crystals of K2W2O7 could be synthesized from a mixture of K2WO4 + WO3 at 40kbar, 1000 °C. The crystals are monoclinic, space group P21/c, with a = 3.883(1) A, b = 13.653(4) Å, c = 5.960(1) Å, β = 90.40(3)°, and Ζ = 2.The structure is comprise of distorted WO6-octahedra (W–O = 1.75-2.13 A) which are connected by corner- and edgesharing, thus forming layers with a sequence ABAB ... along [010]. The potassium ions are situated between the layers with K–O distances of 2.66-3.04 A.Rb2W2O7, synthesized from a Rb2WO4/WO3-mixture at 40 kbar, 1000 °C, is isostructural with K2W2O7 (a = 3.9645(4) Å, b = 14.119(1) Å, c = 6.0415(5) Å,β = 90.446(9)°.

Ein Orthoperrhenat mit flächenverknüpften ReO6-Oktaedern: Hochdrucksynthese und Kristallstruktur von K3NaRe2O9 / An Orthoperrhenate with Face-Sharing ReO6 Octahedra: High-Pressure Synthesis and Crystal Structure of K3NaRe2O9

1993 ◽  
Vol 48 (2) ◽  
pp. 237-239 ◽  
Author(s):  
Klaus-Jürgen Range ◽  
Alexandra Atzesdorfer
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Title Compound ◽  
Technical Grade ◽  
Synthesis And Crystal Structure ◽  
Space Group ◽  
High Pressure Synthesis ◽  
Pressure Synthesis ◽  
High Pressure Reaction ◽  
Type Apparatus

AbstractThe title compound was prepared by high-pressure reaction of rhenium metal with technical grade (i.e., Na containing) KO2 in a modified Belt-type apparatus (20 kbar, 1000 °C, 60 min, Au capsule). The amber-coloured crystals are very hygroscopic and decompose rapidly when exposed to air. K3NaRe2O9 crystallizes hexagonally, space group P63/mmc, with a = 6.012(1), c = 14.342(14) Å, c/a = 2.386 and Z = 2. The structure was refined to R = 0.031, Rw = 0.023 for 422 independent, absorption-corrected reflections with l > σ (I). K3NaRe2O9 is isostructural with 6H-BaTiO3, a perowskite variant, and contains Na and Re in octaedral coordination. Two ReO6 octahedra are face-sharing, thus creating a Re2O9 double octahedron with a Re-R e distance of 2.92 Å.

Benzo-18-krone-6 -Acetonitril (1/2): Kristallisation und Tieftemperatur- Röntgenstrukturanalyse / Benzo-18 -crown-6 -Acetonitrile (1/2): Crystallization and Low-Temperature X-Ray Analysis

1998 ◽  
Vol 53 (12) ◽  
pp. 1528-1530 ◽  
Author(s):  
Karna Wijaya ◽  
Oliver Moers ◽  
Armand Blaschette ◽  
Peter G. Jones
Keyword(s):  
Crystal Structure ◽  
Low Temperature ◽  
Data Collection ◽  
Single Crystals ◽  
Title Complex ◽  
Monoclinic Space Group ◽  
Hydrogen Atoms ◽  
Space Group ◽  
X Ray ◽  
Mecn Solution

Abstract Benzo-18 -crown-6 -Acetonitrile (1/2), Crystal Structure Single crystals of the title complex resulted fortuitously during an attempt to co-crystallise MeN(SO2Me)2 with benzo-18-crown-6 from an MeCN solution at -30 °C. The crystal structure has been determined via data collection at -100 °C (monoclinic, space group P21/n, Z = 4). The nitrile molecules are located with their me­ thyl groups above and below the plane of the 18-membered crown ring, the Me hydrogen atoms being rotationally disordered about the MeCN axes; C(methyl)···O(crown) distances range from 309.4(3) to 384.9(3) pm.

A New Allotropic Form of Bi2O3

1998 ◽  
Vol 547 ◽  
Author(s):  
N. Kumada ◽  
N. Kinomura
Keyword(s):  
Crystal Structure ◽  
Low Temperature ◽  
Single Crystals ◽  
Bismuth Oxide ◽  
Hydrothermal Reaction ◽  
Starting Material ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
Allotropic Form ◽  
R Factors

AbstractSingle crystals of a new allotropic form of bismuth sesquioxide, Bi2O3 were prepared by low temperature hydrothermal reaction using hydrated sodium bismuth oxide, NaBiO3·nH2O, as a starting material. This bismuth oxide crystallized in the orthorhombic space group Pccn with a=12.732(2), b=4.955(2) and c=5.582(2)Å, z=4, and the R-factors were R=0.030 and Rw=0.030 for 1702 unique reflections. The crystal structure is built up by corner- and edge-sharing of irregular BiO5 polyhedra and the tunnel is running along the c-axis.

Synthese und Kristallstrukturen von N-[ω-(Dimethylammonio)alkyl]- N´,N´,N´´,N´´-tetramethylguanidinium-chlorid-tetraphenylboraten / Synthesis and Crystal Structures of N-[ω-(Dimethylammonio)alkyl]-N´,N´,N´´,N´´- tetramethylguanidinium Chloride Tetraphenylborates

2010 ◽  
Vol 65 (7) ◽  
pp. 907-916 ◽  
Author(s):  
Ioannis Tiritiris ◽  
Falk Lissner ◽  
Thomas Schleid ◽  
Willi Kantlehner
Keyword(s):  
Crystal Structure ◽  
Low Temperature ◽  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Room Temperature ◽  
Chloride Ions ◽  
Monoclinic Space Group ◽  
Temperature Structure ◽  
Space Group ◽  
Temperature Modification

Dicationic N,N´,N´,N´´,N´´-pentasubstituted guanidinium dichlorides 4a, b are obtained from the chloroformamidinium salt 2 and diamines 3a, b. N-[2-(Dimethylammonio)ethyl]-N´,N´,N´´,N´´-tetramethylguanidinium chloride tetraphenylborate (5a) and N-[3-(dimethylammonio)propyl]-N´,N´,N´´,N´´-tetramethylguanidinium chloride tetraphenylborate (5b) were synthesized from 4a, b by anion metathesis with one equivalent of sodium tetraphenylborate. The thermal properties of the salts 5a, b were studied by means of DSC methods, and their crystal structures were determined by single-crystal X-ray diffraction analysis. For 5a a solid-solid phase transition is observed at −156 ◦C to a low-temperature structure. The room-temperature modification (α-5a) crystallizes in the centrosymmetric orthorhombic space group Pbca (a = 13.1844(4), b = 13.8007(4), c = 34.7537(11) A° ).The guanidinium ions are interconnected via chloride ions through bridging N-H· · ·Cl hydrogen bonds, providing isolated units. The tetraphenylborate ions show some dynamic disordering in the crystal structure. The low-temperature modification (β -5a) also crystallizes orthorhombically, but in the non-centrosymmetric space group Pna21 (a = 13.1099(4), b = 69.1810(11), c = 13.5847(5) A° ) and consists of four crystallographically independent cations and anions in the unit cell. Compared with the room-temperature structure, a similar N-H· · ·Cl hydrogen bond pattern is observed in the β -phase, but the tetraphenylborate ions are now completely ordered. 5b crystallizes in the monoclinic space group P21/c (a = 10.8010(3), b = 14.1502(5), c = 20.9867(9) A° , β = 94.322(1)◦). In the crystal structure the guanidinium ions are linked via chloride ions through N-H· · ·Cl hydrogen bonds, but in contrast to 5a two infinite strands are formed along the a axis with the tetraphenylborate ions interspersed between them for charge compensation.

Notizen: Zur Kristallstruktur von SrPbO3 / The Crystal Structure of SrPbO3

1975 ◽  
Vol 30 (3-4) ◽  
pp. 277-278 ◽  
Author(s):  
Hans-L. Keller ◽  
Karl-H. Meier ◽  
Hk. Müller-Buschbaum
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Single Crystal ◽  
Single Crystals ◽  
Diffraction Data ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Pressure Synthesis ◽  
Group D

Single crystals of SrPbO3 could be prepared by oxygen-high-pressure-synthesis (PO2 > 3500 at, t = 450°C). Single crystal X-ray diffraction data confirm the space group D2h16-Pnma. SrPbO3 belongs to the orthorhombic distorted Perowskit type with a = 5.964, b = 8.320, c = 5.860 Å. The atomic positions were refined.

Low-Temperature Structure and Magnetic Properties of Tetraphenylarsonium Tetrachloronitridotechnetate(VI)

1996 ◽  
Vol 49 (5) ◽  
pp. 633 ◽  
Author(s):  
BN Figgis ◽  
PA Reynolds ◽  
FK Larsen ◽  
GA Williams ◽  
CD Delfs
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
Low Temperature ◽  
Neutron Diffraction ◽  
Single Crystals ◽  
Temperature Structure ◽  
X Ray Diffraction ◽  
Magnetic Susceptibilities ◽  
Space Group ◽  
X Ray

The crystal structure of [As(C6H5)4] [TcNCl4] was determined at 120 K by X-ray diffraction and at 28 K by neutron diffraction. The crystals are tetragonal, space group P4/n, with a 1260.4(3) and c 773.2(2) pm at 120 K. The [TcNCl4]-anion possesses exact C4v symmetry, with Tc≡N distances of 160.3(2) and 162.5(4)pm at 120 and 28 K respectively. Magnetic susceptibilities were measured on single crystals from 300 to 4.5 K. The results indicate a well behaved S ½ system following the Curie-Weiss law with θ -0.13 K

Eine neue Modifikation von Lanthanmonogermanid – lT-LaGe /A New Modification of Lanthanummonogermanide – lT-LaGe

2004 ◽  
Vol 59 (5) ◽  
pp. 559-561 ◽  
Author(s):  
Hansjürgen Mattausch ◽  
Arndt Simon
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Single Crystals ◽  
Structure Type ◽  
Space Group ◽  
Temperature Modification ◽  
Moisture Sensitive ◽  
High Temperature Modification ◽  
Trigonal Prisms

Abstract Single crystals of the low temperature modification of LaGe are obtained as a byproduct in the reaction of La metal, LaBr3 and Ge powder at 1000 °C as silver colored, moisture sensitive needles. lT-LaGe crystallizes in space group Cmcm with a = 4.5590(10), b = 13.766(2), c = 6.745(2)Å . The Ge atoms form cis-trans-cis-trans-chains with dGe−Ge = 2.621(1) and 2.799(1) Å in contrast to Ge zigzag chains found in the high temperature modification of LaGe crystallizing in the FeB structure type. In both structures the Ge atoms are surrounded by trigonal prisms of lanthanum atoms with CN = 6+1 but different connection of the prisms.

scholarly journals Die Kristallstruktur von Mangantetrafluorid The Crystal / Structure of Manganese Tetrafluoride

1987 ◽  
Vol 42 (9) ◽  
pp. 1102-1106 ◽  
Author(s):  
Bernd G. Müller ◽  
Michael Serafin
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Single Crystals ◽  
Lattice Energy ◽  
Space Group ◽  
Dark Blue

Single crystals of dark blue MnF4 have been obtained by high pressure fluorination (pF2 = 3 kbar) of MnF2. There exist two modifications: α-MnF4 crystallizes tetragonally body centered with a = 12.63(1), c = 6.049(5) Å, space group I41/a-C4h6 (No. 88). Z = 16; the structure of β-MnF4, (probably) rhombohedral with a = 19.56(2). c = 13.00(1) Å, Z = 72, is yet unknown in detail. MnF4 is paramagnetic with ,μeff (301.2 K) = 3.87 B. M. . The Curie-Weiss law is obeyed down to 22.4 K; the Madelung Part of lattice energy (MAPLE) is calculated to be 2475 kcal/mol.

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