Powder X-ray diffraction analysis of the ferroelectric liquid crystal with a 2-methylbutoxypropionate unit as a function of temperature

2003 ◽  
Vol 18 (4) ◽  
pp. 293-295 ◽  
Author(s):  
L. Dobiášová ◽  
H. Šíchová ◽  
V. Valvoda
Keyword(s):  
Liquid Crystal ◽  
Diffraction Analysis ◽  
Small Variation ◽  
Ferroelectric Liquid Crystal ◽  
X Ray Diffraction ◽  
Layer Spacing ◽  
X Ray ◽  
Temperature Range ◽  
Liquid Crystal Material ◽  
Intermolecular Distances

The ferroelectric liquid crystal material [4-[(4-methyloxyfenyl) carbonyloxyl] bifenyl-4′-yl]-(S)-2-methylbutoxypropionate containing a lateral methyl group on the aromatic ring of the alkoxybenzoate unit and two chiral carbons has been investigated by X-ray powder diffraction analysis at the 28 °C–105 °C temperature range. On cooling through the SmC temperature range, the layer spacing decreases from 28.3 to 27.7 Å with a small variation of average intermolecular distances. Lattice parameters of tetragonal and monoclinic crystalline phases occurring at lower temperatures have been determined.

scholarly journals The peculiar optic, dielectric and X‐ray diffraction properties of a fluorinated de Vries asymmetric diffuse cone‐model ferroelectric liquid crystal

2006 ◽  
Vol 33 (1) ◽  
pp. 17-23 ◽  
Author(s):  
Jan P. F. Lagerwall ◽  
David Coleman ◽  
Eva Körblova ◽  
Chris Jones ◽  
Renfan Shao ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Ferroelectric Liquid Crystal ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cone Model ◽  
De Vries

X-ray microdiffraction study of the half-V-shaped switching liquid crystal

2004 ◽  
Vol 19 (1) ◽  
pp. 53-55 ◽  
Author(s):  
Kazuhiro Takada ◽  
Takashi Noma ◽  
Takeshi Togano ◽  
Taihei Mukaide ◽  
Atsuo Iida
Keyword(s):  
Phase Transition ◽  
Liquid Crystal ◽  
Formation Process ◽  
Ferroelectric Liquid Crystal ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transient Layer ◽  
Smectic C ◽  
Layer Structures ◽  
Temperature Controlled

Local layer structures and their formation process in a half-V-shaped switching ferroelectric liquid crystal (HV-FLC) were investigated by means of synchrotron X-ray microdiffraction. The HV-FLC is a FLC that has a cholesteric–chiral smectic C (Ch–SmC*) phase transition sequences. X-ray microdiffraction measurements revealed that the SmC* phase in the HV-FLC was composed of asymmetric chevron and inclined-bookshelf structures. In addition, temperature-controlled X-ray diffraction measurements showed that the transient layer structures appeared during the Ch to SmC* phase transition.

scholarly journals Chiral 1,2-Subnaphthalocyanines

2021 ◽  
Author(s):  
Soji Shimizu ◽  
Akito Miura ◽  
Tebello Nyokong ◽  
Samson Khene ◽  
Nagao Kobayashi
Keyword(s):  
Diffraction Analysis ◽  
Magnetic Circular Dichroism ◽  
Small Variation ◽  
Soret Band ◽  
Chiral Molecules ◽  
X Ray Diffraction ◽  
Enantiomerically Pure ◽  
X Ray ◽  
First Time ◽  
The Relationship

<p>Following the first suggestion of inherent molecular chirality in asymmetrically substituted subphthalocyanines by Torres and co-workers in 2000, elucidation of the relationship between structure and chirality has become an important issue. However, separation of the enantiomers has been prevented by the low solubility of the molecules synthesized to date, and it has not been possible to link the CD signs and intensities to their absolute structures. Recently, we observed that 1,2-subnaphthalocyanines possess two diastereomers with respect to the arrangement of the naphthalene moieties and that these novel chiral molecules exhibit moderate solubility in common organic solvents. This has enabled us to separate all of the diastereomers and enantiomers. The two diastereomers have been completely characterized by NMR spectroscopy and X-ray diffraction analysis. The absorption and magnetic circular dichroism spectra, together with theoretical calculation, reveal a small variation in the frontier molecular orbitals of the 1,2-subnaphthalocyanines compared with conventional subphthalocyanines, except for destabilization of the HOMO–3, which results in a characteristic absorption in the Soret band region. The chirality of 1,2-subnaphthalcyanines, including the CD signs and intensities, is discussed in detail for the first time with enantiomerically pure molecules whose absolute structures have been elucidated by single-crystal X-ray diffraction analysis.</p>

scholarly journals Структурные особенности замещенного феррита стронция Sr-=SUB=-1-x-=/SUB=-La-=SUB=-x-=/SUB=-FeO-=SUB=-3-delta-=/SUB=-: I. Sr-=SUB=-2-=/SUB=-LaFe-=SUB=-3-=/SUB=-O-=SUB=-9-delta-=/SUB=-

2021 ◽  
Vol 63 (10) ◽  
pp. 1648
Author(s):  
В.Д. Седых ◽  
О.Г. Рыбченко ◽  
Н.В. Барковский ◽  
А.И. Иванов ◽  
В.И. Кулаков
Keyword(s):  
Heat Treatment ◽  
Diffraction Analysis ◽  
Rhombohedral Phase ◽  
Structural Features ◽  
Structure Evolution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Range ◽  
Treatment Conditions ◽  
Valence States

The structural features and Fe valence states in the substituted strontium ferrite Sr2/3La1/3FeO3-δ (or Sr2LaFe3O9-δ) have been studied for different synthesis and heat treatment conditions by X-ray diffraction analysis and Mossbauer spectroscopy. A series of annealing of Sr2LaFe3O9-δ in vacuum ((10-3 Torr) in the temperature range of 400 - 650оС allowed us to trace the structure evolution from rhombohedral phase (Sr2LaFe3O9) to orthorhombic one (Sr2LaFe3O8) over the formation of intermediate multiphase states and the redistribution of Fe valence states as well.

X-ray diffraction study of phase transition of ferroelectric liquid crystal DOBAMBC

1984 ◽  
Vol 4 (3) ◽  
pp. 225-239
Author(s):  
M. Hidaka ◽  
H. Akiyama ◽  
S. Kai ◽  
M. Iwasaki
Keyword(s):  
Phase Transition ◽  
Liquid Crystal ◽  
Diffraction Study ◽  
Ferroelectric Liquid Crystal ◽  
X Ray Diffraction ◽  
X Ray

Synthesis and liquid crystal behavior of tris[2,3,9,10,16,17,23,24-octakis(octyloxy)phthalocyaninato] rare earth complexes

2007 ◽  
Vol 11 (02) ◽  
pp. 100-108 ◽  
Author(s):  
Ying Zhang ◽  
Weili Jiang ◽  
Jianzhuang Jiang ◽  
Qingbin Xue
Keyword(s):  
Rare Earth ◽  
Liquid Crystal ◽  
Liquid Crystalline ◽  
Optical Microscope ◽  
Rare Earth Complexes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Range ◽  
Ionic Size ◽  
Liquid Crystal Phase Transition

A series of tris[2,3,9,10,16,17,23,24-octakis(octyloxy)phthalocyaninato] rare earth(III) complexes M 2[ Pc ( OC 8 H 17)8]3 [ M = Eu , Gd , Y , Lu ] has been prepared by the reaction of corresponding bis[2,3,9,10,16,17,23,24-octakis(octyloxy)phthalocyaninato] rare earth complexes with M ( acac )3·n H 2 O in refluxing 1,2,4-trichlorobenzene. These liquid crystalline sandwich, triple-decker complexes were characterized by elemental analysis and various spectroscopic methods including 1 H NMR, UV-vis, IR and mass spectroscopies. Their liquid crystal phase transition behavior was studied by Polarized Optical Microscope, Differential Scanning Calorimeter and X-ray diffraction. The complexes, with octyloxy attached as side chains, showed rectangular columnar liquid crystal phases in a liquid crystal temperature range between 83 and 305°C. In addition to the rare earth contraction, both the transition temperature and the wide temperature range of the mesophase show a slight but obvious trend to decrease, respectively, in the same order. In contrast, the molecular packing of these complexes as revealed by X-ray diffraction was found to be almost independent of the ionic size of the central rare earth.

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