Orientational disorder in solids composed of the ellipsoid-shaped molecules trichloromethyltrimethylsilane, Cl3CSi(CH3)3, t-Butyltrichlorosilane, (CH3)3CSiCl3, and t-Butyldimethylchlorosilane, (CH3)3CSi(CH3)2Cl

1994 ◽  
Vol 98 (8) ◽  
pp. 1096-1099 ◽  
Author(s):  
Sigmar Bräuninger ◽  
Shi-Qi Dou ◽  
Hartmut Fuess ◽  
Wolfgang Schmahl ◽  
Roman Strauß ◽  
...  
Keyword(s):  
Orientational Disorder

scholarly journals Crystallographic features of ammonium fluoroelpasolites: dynamic orientational disorder in crystals of (NH4)3HfF7 and (NH4)3Ti(O2)F5

2017 ◽  
Vol 73 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Anatoly A. Udovenko ◽  
Alexander A. Karabtsov ◽  
Natalia M. Laptash
Keyword(s):  
Single Crystal ◽  
Electron Density ◽  
Diffraction Data ◽  
Central Atom ◽  
X Ray Diffraction ◽  
Dynamic Nature ◽  
Orientational Disorder ◽  
High Quality ◽  
Structural Units ◽  
X Ray

A classical elpasolite-type structure is considered with respect to dynamically disordered ammonium fluoro-(oxofluoro-)metallates. Single-crystal X-ray diffraction data from high quality (NH4)3HfF7 and (NH4)3Ti(O2)F5 samples enabled the refinement of the ligand and cationic positions in the cubic Fm \bar 3 m (Z = 4) structure. Electron-density atomic profiles show that the ligand atoms are distributed in a mixed (split) position instead of 24e. One of the ammonium groups is disordered near 8c so that its central atom (N1) forms a tetrahedron with vertexes in 32f. However, a center of another group (N2) remains in the 4b site, whereas its H atoms (H2) occupy the 96k positions instead of 24e and, together with the H3 atom in the 32f position, they form eight spatial orientations of the ammonium group. It is a common feature of all ammonium fluoroelpasolites with orientational disorder of structural units of a dynamic nature.

Orientational disorder in lithium sodium sulfate

1995 ◽  
Vol 102 (17) ◽  
pp. 6941-6945 ◽  
Author(s):  
Gamini Dharmasena ◽  
Roger Frech
Keyword(s):  
Sodium Sulfate ◽  
Orientational Disorder

Separation of Orientational Disorder in the X-Ray Analysis of the Kinetically Stabilized 2-Silanaphthalene

2000 ◽  
Vol 73 (9) ◽  
pp. 2157-2158 ◽  
Author(s):  
Keiji Wakita ◽  
Norihiro Tokitoh ◽  
Renji Okazaki
Keyword(s):  
Orientational Disorder ◽  
X Ray

Orientational Disorder in Chiral Bilayer Dielectric Metasurfaces

2021 ◽  
Author(s):  
Katsuya Tanaka ◽  
Aso Rahimzadegan ◽  
Dennis Arslan ◽  
Stefan Fasold ◽  
Michael Steinert ◽  
...  
Keyword(s):  
Orientational Disorder ◽  
Bilayer Dielectric

scholarly journals Orientational disorder in plastic neopentane (paralipomena)

1987 ◽  
Vol 48 (9) ◽  
pp. 1513-1519 ◽  
Author(s):  
Ph. Depondt ◽  
M. Debeau
Keyword(s):  
Orientational Disorder

scholarly journals Orientation Ordering and Chiral Superstructures in Fullerene Monolayer on Cd (0001)

Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1305
Author(s):  
Yuzhi Shang ◽  
Zilong Wang ◽  
Daxiao Yang ◽  
Yaru Wang ◽  
Chaoke Ma ◽  
...  
Keyword(s):  
Thin Films ◽  
Charge Transfer ◽  
Scanning Tunneling Spectroscopy ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Orientational Disorder ◽  
Temperature Scanning ◽  
Orientation Ordering ◽  
The Individual ◽  
Misorientation Angles

The structure of C60 thin films grown on Cd (0001) surface has been investigated from submonolayer to second monolayer regimes with a low-temperature scanning tunneling microscopy (STM). There are different C60 domains with various misorientation angles relative to the lattice directions of Cd (0001). In the (2√3 × 2√3) R30° domain, orientational disorder of the individual C60 molecules with either pentagon, hexagon, or 6:6 bond facing up has been observed. However, orientation ordering appeared in the R26° domain such that all the C60 molecules adopt the same orientation with the 6:6 bond facing up. In particular, complex chiral motifs composed of seven C60 molecules with clockwise or anticlockwise handedness have been observed in the R4° and R8° domains, respectively. Scanning tunneling spectroscopy (STS) measurements reveal a reduced HOMO–LOMO gap of 2.1 eV for the C60 molecules adsorbed on Cd (0001) due to the substrate screening and charge transfer from Cd to C60 molecules.

Alkylammonium hexachlorostannates(IV), (RnNH4−n)2SnCl6: crystal structure, infrared spectrum, and hydrogen bonding

1983 ◽  
Vol 61 (7) ◽  
pp. 1620-1646 ◽  
Author(s):  
Osvald Knop ◽  
T. Stanley Cameron ◽  
Margaret Ann James ◽  
Michael Falk
Keyword(s):  
Hydrogen Bonding ◽  
Room Temperature ◽  
Fermi Resonance ◽  
Molecular Volume ◽  
Site Symmetry ◽  
Dilution Technique ◽  
Orientational Disorder ◽  
Anomalous Temperature ◽  
Ammonium Compounds ◽  
Anion Packing

In an effort to advance our understanding of the principles governing the structures of and the hydrogen bonding in alkylammonium hexachlorostannates(IV), (RnNH4−n)2SnCl6, we have determined the room-temperature crystal structures of (Me2NH2)2SnCl6 and (Me3NH)2SnCl6 (variants of the antifluorite structure); (EtNH3)2SnCl6 and (n-PrNH3)2SnCl6 (anti-Cdl2 type, with orientational disorder in the Et compound); and (n-Pr3NH)2SnCl6. We have also studied the infrared spectra in the regions of the NH and ND stretching fundamentals, between 10 and 293 K, of these five compounds and of (MeNH3)2SnCl6, (Me3NH)2SnBr6, (Et2NH2)2SnCl6, (n-Bu3NH)2SnCl6 and, in less detail, the mixed-anion salt (n-Pr2NH2)3(SnCl6)Cl. The spectra are often complicated by Ferim resonance involving absorptions diagnostically critical for the strength and type of [Formula: see text] bonding and for the site symmetry at the N atom. In this respect they are less useful than the corresponding spectra of the unsubstituted ammonium compounds reported previously. Several of the spectra provide striking examples of temperature-tuned Fermi resonance of NH and ND vibrations. The [Formula: see text] bonds are invariably trifurcated, bifurcated, or at least highly bent; these characteristics give rise to anomalous temperature dependence of the frequencies of the NH and ND stretching fundamentals. Temperature-induced transitions were detected in (Me2NH2)2SnCl6 (Ttr ~ 100 K), Et NH3)2SnCl6 (Ttr ~ 125 K), and (Et2NH2)2SnCl6 (Ttr ~ 330 K). The specific results for the ten compounds studied arc discussed in detail. The discussion also includes the limits of usefulness of the isotopisc dilution technique; symmetry aspects of the cation–anion packing in alkylammonium hexahalometallates(IV); symmetries of the arrangements of the SnCl6 octahedra; the geometry of hydrogen bonding in (RnNH4−n)2SnCl6; and the possibility of detection of the presence of hydrogen bonding from molecular volume trends.

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