ChemInform Abstract: Crystal Structure of Low Temperature Modification of LuNiPb.

ChemInform ◽  
2008 ◽  
Vol 39 (37) ◽  
Author(s):  
L. D. Gulay
Keyword(s):  
Crystal Structure ◽  
Low Temperature ◽  
Temperature Modification

scholarly journals Crystal structure of the low-temperature modification of trilithium heptaarsenide, LT-Li3As7

2002 ◽  
Vol 217 (1) ◽  
pp. 485-486
Author(s):  
W. Hönle ◽  
J. Buresch ◽  
K. Peters ◽  
J. H. Chang ◽  
H. G. von Schnering
Keyword(s):  
Crystal Structure ◽  
Low Temperature ◽  
Temperature Modification

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.

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.

scholarly journals Crystal structure of the low-temperature modification of trirubidium heptaarsenide, LT-Rb3As7

2002 ◽  
Vol 217 (JG) ◽  
pp. 489-490 ◽  
Author(s):  
W. Hönle ◽  
J. Buresch ◽  
J. Wolf ◽  
K. Peters ◽  
J.-H. Chang ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Low Temperature ◽  
Temperature Modification
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