scholarly journals Crystal Structure Analysis of LaCrO3 System II. Phase Transition and Thermal Expansion of Cation-Substituted LaCrO3

1999 ◽  
Vol 1999-19 (1) ◽  
pp. 657-665 ◽  
Author(s):  
K. Yoshida
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Thermal Expansion ◽  
Structure Analysis ◽  
Crystal Structure Analysis

Crystal Structure Analysis and Phase Transition in Lead Orthovanadate Pb3(VO4)2

1992 ◽  
Vol 61 (7) ◽  
pp. 2309-2316 ◽  
Author(s):  
Hirofumi Kasatani ◽  
Takashi Umeki ◽  
Hikaru Terauchi
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Structure Analysis ◽  
Crystal Structure Analysis

Isolated versus Condensed Anion Structure III: The Influence of the Cations 1,3-propanediammonium, 1,4-butanediammonium, /n-propylammonium, /n-butylammonium and /n-pentylammonium on Structures and Phase Transitions of ZnBr42- Salts. A81 Br NQR and X-ray Structure Analysis

1997 ◽  
Vol 52 (6-7) ◽  
pp. 550-560 ◽  
Author(s):  
Hideta Ishihara ◽  
Shi-qi Dou ◽  
Keizo Horiuchi ◽  
Helmut Paulus ◽  
Hartmut Fuess ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Phase Transitions ◽  
Hydrogen Bonds ◽  
Structure Analysis ◽  
Phase Ii ◽  
Crystal Structure Analysis ◽  
X Ray ◽  
Dsc Measurements

Abstract The influence of the cations on the condensation of the anions in the salts (A´)Zn(II) Br4 and (A) 2 Zn(II)Br4 is studied by 81Br NQR and X-ray crystal structure analysis. (A´)Zn(II)Br4 (A´ = [H3N(CH2)3NH3]2+) (1) shows a phase transition at 474 K. The phase II of (1) crystallizes with isolated [ZnBr4]2- tetrahedra: monoclinic P21 /n, Z = 4, a = 1108.4 (5), b = 1096.8 (2), c = 1118.5 (6) pm, and β= 117.07(4)° at 296 K. A quartet was observed in the 81Br NQR spectrum of phase II: 61.634,58062, 56.675, and 53.673 MHz (77K); 59.193, 57.448, 56.015, and 52.515 MHz (301 K).(A)2 ZnBr4 (A = [n-H3C(CH2)2NH3 ]+ (2) and [n-H3C(CH2)3NH3 ]+ (3)) also show structures with isolated [ZnBr4]2- tetrahedra. The compound (2) crystallizes with P21/c, Z = 4, a = 771.8(3), b = 1061.9(4), c = 2054.2 (7) pm, and β = 106.75(1)° at 291 K. The compound (3) crystallizes with P21/c, Z = 4, a = 768.9(4), b = 2229.6(10), c = 1071.6(5) pm, and β = 91.70(3)° at 295 K. 81Br NQR and DSC measurements on [H3N(CH2)4 NH3]ZnBr4 (4), and [n-H3 C(CH2)4NH3]2ZnBr4 (5) were also performed. The compound (4) shows several phase transitions at 349 K and higher temperatures, and a quartet in the 81r NQR spectrum could be observed between 77 and 330 K: 65.992,65.544, 59.900, and 50.162 MHz (77 K); 63.787, 62.963, 59.928, and 50.364 MHz (320 K). The compound (5) shows also a phase transition at 244 K, and a quartet of 81Br lines could be observed in the NQR spectrum between 77 and 244 K: 61.279, 58.933, 57.869, and 56.485 MHz (77 K); 59.712, 56.936, 57.409, and 54.793 MHz (240 K). The various influences of the cations, such as size and hydrogen bonds on the condensation of [MX4]2-(M = Zn, Cd; X = C1, Br) are discussed.

Phase transition of tetrakis(octylthio)tetrathiafulvalene (TTC8–TTF) and crystal structure analysis

1991 ◽  
Vol 1 (1) ◽  
pp. 37-41 ◽  
Author(s):  
Chikako Nakano ◽  
Kenichi Imaeda ◽  
Takehiko Mori ◽  
Yusei Maruyama ◽  
Hiroo Inokuchi ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Structure Analysis ◽  
Crystal Structure Analysis

(H2dabco)[Na(BF4)3]: an ABX3-type inorganic–organic hybrid perovskite compound exhibiting dielectric switching above room-temperature

CrystEngComm ◽  
2019 ◽  
Vol 21 (46) ◽  
pp. 7043-7047 ◽  
Author(s):  
Le Ye ◽  
Zhi-Xin Gong ◽  
Chao Shi ◽  
Jia-Jun Ma ◽  
Hao Liang ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Structure Analysis ◽  
Room Temperature ◽  
Crystal Structure Analysis ◽  
Organic Hybrid ◽  
Dynamic Phase ◽  
Hybrid Perovskite ◽  
Dynamic Phase Transition

The (H2dabco)[Na(BF4)3] undergoes a static-to-dynamic phase transition at 403/386 K. Crystal structure analysis reveals that H2dabco2+ and/or BF4− undergo disordering.

Crystal structure analysis in (3 d) dimensions

1989 ◽  
Vol 16 (1) ◽  
pp. 119-123
Author(s):  
D. Kucharczyk
Keyword(s):  
Crystal Structure ◽  
Structure Analysis ◽  
Crystal Structure Analysis

Crystal structure analysis of 4-R-phenyl-2,6-dimethyl-3,5-N-(dimethylcarbamoyl)-1,4-dihydropyridines [R=2-nitro (1), 4-methoxy (2) and 3,4-dichloro (3)]

1998 ◽  
Vol 213 (3) ◽  
Author(s):  
M. Bidya Sagar ◽  
K. Ravikumar ◽  
Y. S. Sadanandam
Keyword(s):  
Crystal Structure ◽  
Calcium Channel ◽  
Structure Analysis ◽  
Crystal Structure Analysis ◽  
Calcium Channel Antagonists

AbstractThe crystallographic characterization of the following three calcium channel antagonists is reported here: 2,6-dimethyl-3,5-dicarbamoyl-4-[2-nitro]-1,4-dihydropyridine (

scholarly journals Combined Use of Structure Analysis, Studies of Molecular Association in Solution, and Molecular Modelling to Understand the Different Propensities of Dihydroxybenzoic Acids to Form Solid Phases

Pharmaceutics ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 734
Author(s):  
Aija Trimdale ◽  
Anatoly Mishnev ◽  
Agris Bērziņš
Keyword(s):  
Crystal Structure ◽  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Structure Analysis ◽  
Crystal Structure Analysis ◽  
Molecular Association ◽  
Hydroxyl Groups ◽  
Solid Phases ◽  
Solvent Molecules ◽  
Dynamics Simulations

The arrangement of hydroxyl groups in the benzene ring has a significant effect on the propensity of dihydroxybenzoic acids (diOHBAs) to form different solid phases when crystallized from solution. All six diOHBAs were categorized into distinctive groups according to the solid phases obtained when crystallized from selected solvents. A combined study using crystal structure and molecule electrostatic potential surface analysis, as well as an exploration of molecular association in solution using spectroscopic methods and molecular dynamics simulations were used to determine the possible mechanism of how the location of the phenolic hydroxyl groups affect the diversity of solid phases formed by the diOHBAs. The crystal structure analysis showed that classical carboxylic acid homodimers and ring-like hydrogen bond motifs consisting of six diOHBA molecules are prominently present in almost all analyzed crystal structures. Both experimental spectroscopic investigations and molecular dynamics simulations indicated that the extent of intramolecular bonding between carboxyl and hydroxyl groups in solution has the most significant impact on the solid phases formed by the diOHBAs. Additionally, the extent of hydrogen bonding with solvent molecules and the mean lifetime of solute–solvent associates formed by diOHBAs and 2-propanol were also investigated.

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