Crystal Structure of the High-temperature Solid Phases of Choline Tetrafluoroborate and Iodide

1997 ◽  
Vol 52 (8-9) ◽  
pp. 679-680 ◽  
Author(s):  
Hiroyuki Ishida ◽  
Hiroshi Ono ◽  
Ryuichi Ikeda
Keyword(s):  
Crystal Structure ◽  
Phase Transitions ◽  
High Temperature ◽  
Solid Phase ◽  
Temperature Phase ◽  
X Ray ◽  
Cscl Type ◽  
Enthalpy And Entropy Changes ◽  
Enthalpy And Entropy ◽  
Solid Phases

Abstract The crystal structure of the highest-and second highest-temperature solid phases of choline tetrafluoroborate and iodide was determined by X-ray powder diffraction. The structure in the highest-temperature phase of both salts is NaCl-type cubic (a = 10.16(2) Å, Z = 4 for tetrafluorobo-rate; a = 10.08(2) Å, Z = 4 for iodide). The second highest-temperature phase of tetrafluoroborate and iodide is CsCl-type cubic (a = 6.198(6) Å and Z = 1) and tetragonal (a = 8.706(2) Å, c = 6.144(6) Å, and Z = 2), respectively. DSC was carried out for the iodide, where the presence of three solid-solid phase transitions was confirmed. Enthalpy and entropy changes of these transitions were evaluated.

Crystal Structure of Trimethylammonium Tetrafluoroborate in Three Solid Phases

2000 ◽  
Vol 55 (9-10) ◽  
pp. 765-768 ◽  
Author(s):  
Hiroyuki Ishida ◽  
Setsuo Kashino ◽  
Ryuichi Ikeda
Keyword(s):  
Crystal Structure ◽  
Phase Iii ◽  
Temperature Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cscl Type ◽  
Lattice Space ◽  
Plastic Phase ◽  
Solid Phases ◽  
Phase Phase

Abstract The crystal structure of (CH3)3 NHBF 4 was studied in three solid phases by X-ray diffraction techniques. The structures of the ionic plastic phase (Phase I) stable above 453 K and Phase II between 384 and 453 K are CsCl-type cubic (a = 5.772(4) Å) and tetragonal (a = 9.815(5) and c = 6.895(5) Å), respectively. The room temperature phase (Phase III) forms a monoclinic lattice (space group P21/m, a = 5.7017(8), b = 8.5724(9), c = 7.444(1) Å, and ß = 102.76(1)°). BF4− ions in this phase were shown to be disordered in four orientations.

X-ray study of the high‐temperature phase transitions in K2ZnCi4

1982 ◽  
Vol 2 (4) ◽  
pp. 277-283 ◽  
Author(s):  
D. Kucharczyk ◽  
W. Paciorek ◽  
J. Kalicińska-Karut
Keyword(s):  
Phase Transitions ◽  
High Temperature ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
X Ray

IV. Order–disorder transitions: solid state kinetics, thermal analyses, X-ray diffraction and electrical conductivity studies in the Ag2SO4–K2SO4 system

1985 ◽  
Vol 63 (2) ◽  
pp. 324-328 ◽  
Author(s):  
M. Sunitha Kumari ◽  
Etalo A. Secco
Keyword(s):  
Electrical Conductivity ◽  
High Temperature ◽  
Reaction Kinetics ◽  
Solid Phase ◽  
Thermal Analyses ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Solid Liquid

Order–disorder transitions occurring in the Ag2SO4–K2SO4 system were investigated by reaction kinetics, thermal analyses, X-ray diffraction, and electrical conductivity techniques. Solid–liquid and solid–solid phase diagrams are reported.The conductivity data in the high temperature phase of the solid resemble superionic conductivity behavior. The higher conductivity of Ag2SO4 with K+ presence relative to pure Ag2SO4 and Ag2−xNaxSO4 compositions support a lattice expansion facilitating higher mobility of ions.The reaction kinetics, X-ray diffraction, and electroconductivity results suggest a relatively open periodic [Formula: see text] sublattice in the high-temperature phase of the sulfate-based systems studied in this series.

Refinement of the crystal structure of the high-temperature phase G 0 in (NH4)2WO2F4 (powder, X-ray, and neutron scattering)

2013 ◽  
Vol 58 (1) ◽  
pp. 129-134 ◽  
Author(s):  
D. M. Novak ◽  
L. S. Smirnov ◽  
A. I. Kolesnikov ◽  
V. I. Voronin ◽  
I. F. Berger ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
Neutron Scattering ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
X Ray

Crystal Structure of Bis(triethylammonium)closo-decahydrodecaborate, [(C2H5)3NH]2[B10H10]

2000 ◽  
Vol 55 (6) ◽  
pp. 499-503 ◽  
Author(s):  
Kathrin Hofmann ◽  
Barbara Albert
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
Powder Diffraction ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
X Ray ◽  
Crystal System ◽  
System A ◽  
Tetragonal Crystal ◽  
Tetragonal Crystal System

The crystal structure of bis(triethylammonium)closo-decahydrodecaborate [bis(triethylammonium) decaboranate(10)], [(C2H5)3NH]2[B10H10], was determined and refined (space group Pmmn, no. 59, a = 989.7, b = 1333.7, c = 903.7 pm). The compound is a versatile starting material for many substances containing the [BioHio]2- entity and its derivatives. The closo-[B10H10]2- cluster is a bicapped square antiprism which is only slightly distorted. Its deviation from D4d symmetry is smaller than that of the B10 cages in every other compound containing this entity that have been structurally characterised. The presence of additional (N )H ---B3 interactions in form of multiple-centre bonds between the cations and the anions, which were postulated earlier and which should influence the cage symmetry, could not be confirmed. At 55 °C, the transition into a high temperature phase was investigated by X-ray powder diffraction. The high temperature phase crystallises in the tetragonal crystal system (a = 946.9, c = 1351.0 pm).

X-ray powder diffraction investigation of new high temperature polymorphs of CaTeO3 and CaTe2O5

2001 ◽  
Vol 16 (4) ◽  
pp. 205-211 ◽  
Author(s):  
S. N. Tripathi ◽  
R. Mishra ◽  
M. D. Mathews ◽  
P. N. Namboodiri
Keyword(s):  
High Temperature ◽  
Powder Diffraction ◽  
Room Temperature ◽  
Solid Phase ◽  
High Temperature Phase ◽  
Unit Cell ◽  
Stable Phase ◽  
Temperature Phase ◽  
X Ray ◽  
Monoclinic Lattice

X-ray powder diffraction investigation of the new high temperature polymorphs beta- and gamma-CaTeO3 and gamma- and delta-CaTe2O5 and picnometric measurements of the room temperature phases of the two compounds have been carried out. The study led to the elucidation of their unit cell structures and assignment of entirely new lattice types and parameters to the room temperature phases of CaTeO3 and CaTe2O5 in contrast and supersession to the existing structural information. The results are as follows: CaTeO3 has only one stable phase at room temperature and temperatures up to 882 °C, i.e., α- and has a triclinic unit cell with a=4.132±0.003 Å, b=6.120±0.006 Å, c=12.836±0.013 Å, α=121.80°, β=99.72°, γ=97.26°. The first high temperature phase stable between 882 and 894 °C, i.e., β-CaTeO3, has a monoclinic lattice: a=20.577±0.007 Å, b=21.857±0.009 Å, c=4.111±0.002 Å, β=96.15°, while the next phase stable above 894 °C, i.e., γ-CaTeO3, has a hexagonal unit cell with parameters: a=14.015±0.0001 Å, c=9.783±0.001 Å, c/a=0.698. CaTe2O5 has one stable phase at temperatures up to 802 °C, i.e., α-CaTe2O5 with a monoclinic lattice and parameters: a=9.069±0.002 Å, b=25.175±0.007 Å, c=3.366±0.001 Å, β=98.29 °. The first high temperature phase stable in the range 802–845°, i.e., β-CaTe2O5, is monoclinic with unit cell parameters: a=4.146±0.001 Å, b=5.334±0.002 Å, c=6.105±0.002 Å, β=98.362 °; the next higher temperature phase stable over 845–857 °C, i.e., γ-CaTe2O5, has an orthorhombic unit cell with: a=8.638±0.001 Å, b=9.291±0.001 Å, c=7.862±0.001 Å and the highest temperature solid phase stable above 857 °C, i.e., δ-CaTe2O5 has a tetragonal unit cell with a=5.764±0.000 Å, c=32.074±0.020 Å, c/a=5.5637.

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