Phase transitions in the A2BX4-compound: Tetramethylammonium tetrachlorozincate tetrachlorocuprate, [(CH3)4N]2Zn0.5Cu0.5Cl4, and room temperature crystal structure determination

2008 ◽  
Vol 53 (5) ◽  
pp. 785-793 ◽  
Author(s):  
F. Hlel ◽  
A. Ben Rhaeim ◽  
K. Guidara
Keyword(s):  
Crystal Structure ◽  
Phase Transitions ◽  
Structure Determination ◽  
Room Temperature ◽  
Crystal Structure Determination

First crystal-structure determination of natural lansfordite, MgCO3·5H2O

2017 ◽  
Vol 81 (5) ◽  
pp. 1063-1071 ◽  
Author(s):  
Fabrizio Nestola ◽  
Anatoly V. Kasatkin ◽  
Sergey S. Potapov ◽  
Olga YA. Chervyatsova ◽  
Arianna Lanza
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Single Crystal ◽  
Structure Determination ◽  
Room Temperature ◽  
Crystal Structure Determination ◽  
Hydrogen Atoms ◽  
Synthetic Analogues ◽  
X Ray

AbstractThis study presents the first crystal-structure determination of natural MgCO3·5H2O, mineral lansfordite, in comparison with previous structural works performed on synthetic analogues. A new prototype single-crystal X-ray diffractometer allowed us to measure an extremely small crystal (i.e. 0.020 mm × 0.010 mm × 0.005 mm) and refine anisotropically all non-hydrogen atoms in the structure and provide a robust hydrogen-bond arrangement. Our new data confirm that natural lansfordite can be stable for several months at room temperature, in contrast with previous works, which reported that such a mineral could be stable only below 10°C.

Kristallographische Konsequenzen von Pseudosymmetrie in Kristallstrukturen

2000 ◽  
Vol 215 (3) ◽  
Author(s):  
M. Ruck
Keyword(s):  
Crystal Structure ◽  
Phase Transitions ◽  
Crystal Structures ◽  
Structure Determination ◽  
Stacking Faults ◽  
Spatial Arrangement ◽  
Crystal Structure Determination ◽  
Small Deviations ◽  
New Class

The term pseudo-symmetry means a spatial arrangement that feigns a symmetry without fulfilling it. In crystal structures pseudo-symmetry is a more common feature than often recognized. In case of small deviations a variety of phenomena results: polytypism and stacking faults, disorder and twinning, commensurate and incommensurate super-structures, phase transitions and unusual reflection conditions. Most of these effects complicate crystal structure determination considerably. A series of examples with focus on the new class of ternary bismuth subhalides illustrates the different crystallographic consequences of pseudo-symmetry in crystal structures.

Crystal Structure of a Heterometallic Luminophore: The RuII Complex of a Ferrocenyl-Terpyridine with a Flexible Linkage

2017 ◽  
Vol 70 (5) ◽  
pp. 632 ◽  
Author(s):  
Young Hoon Lee ◽  
Jong Won Shin ◽  
Yusuke Sekimoto ◽  
Shinya Hayami ◽  
Jack Harrowfield ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Structure Determination ◽  
Room Temperature ◽  
Mixed Ligand Complex ◽  
Mixed Ligand ◽  
Crystal Structure Determination ◽  
Ligand Complex ◽  
Ferrocenyl Group ◽  
Flexible Linkage

Crystal structure determination on the mixed ligand complex [Ru(tpy)(L1)](ClO4)2 (tpy = 2,2′:6′,2″-terpyridine; L1 = 4′-(ferrocenylmethylaminomethylphenyl)terpyridine) shows the ferrocenyl group to be located as remotely as possible from the RuII centre. This may explain the fact that emission from the RuII centre is detectable even at room temperature in solution.

6,7-Dimethyl-3a,8a-dihydro-3H-8-oxacyclopenta[a]inden-5-yl benzoate

2000 ◽  
Vol 57 (1) ◽  
pp. o37-o38
Author(s):  
Mátyás Czugler ◽  
Petra Bombicz
Keyword(s):  
Crystal Structure ◽  
Intramolecular Cyclization ◽  
Structure Determination ◽  
Title Compound ◽  
Room Temperature ◽  
Sigmatropic Rearrangement ◽  
Crystal Structure Determination ◽  
Aryl Ether ◽  
Compound C ◽  
One Step

The title compound, C20H18O3, was prepared in a one-step synthesis by intramolecular cyclization following the sigmatropic rearrangement of the allyl aryl ether intermediate. The room-temperature crystal structure determination reveals acisconformation of the ring annellation.

Synthesis and Single Crystal Structure Determination of Bis(carbido)bis(μ-diphenylphosphido)heptadecacarbonyloctaruthenium-Dichloromethane (1/1), Ru8(μ6-C)(μ5-C)(μ-PPh2)2(CO)17.CH2Cl2

1993 ◽  
Vol 46 (11) ◽  
pp. 1811 ◽  
Author(s):  
CJ Adams ◽  
MI Bruce ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Structure Determination ◽  
Title Compound ◽  
Room Temperature ◽  
Single Crystal Structure ◽  
Crystal Structure Determination ◽  
Triangular Face ◽  
X Ray

The synthesis and room-temperature single-crystal X-ray structure determination of the title compound are recorded. Crystals are monoclinic, P 21/c, a 14.43(2), b 18.39(1), c 23.64(3) Ǻ, β 123.16(7)°, Z = 4, isostructural with the recently described Fe3Ru5 analogue; R was 0.048 for 6892 'observed' data [I > 3σ(I)]. The cluster is one of the few containing separated carbide ligands within a polyhedral metal skeleton, consisting of an Ru5C square pyramid and an Ru6C octahedron sharing a triangular face, with two PPh2 groups bridging opposite Ru-Ru vectors in each polyhedron.

Triethylammonium halides, Et3NHX (X = Cl, Br, I): simple structure, complex spectrum

1985 ◽  
Vol 63 (7) ◽  
pp. 1750-1758 ◽  
Author(s):  
Margaret Ann James ◽  
T. Stanley Cameron ◽  
Osvald Knop ◽  
Murray Neuman ◽  
Michael Falk
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Ir Spectra ◽  
Structure Determination ◽  
Room Temperature ◽  
Simple Structure ◽  
Fermi Resonance ◽  
Crystal Structure Determination ◽  
Complex Spectrum ◽  
Resonance Interactions

A crystal structure determination has shown that the ethyl groups in the three isostructural (P63mc, Z = 2) triethylammonium halides, Et3NHX (X = Cl, Br, I), at room temperature are orientationally disordered and the [Formula: see text] groups are linear by symmetry. The unusual extent and complexity of the NH and ND stretching absorptions in the ir spectra of all three compounds between 10 and 293 K are discussed in terms of Fermi resonance interactions. The centroid ν(NH) and ν(ND) frequencies extracted from the spectra correlate with the [Formula: see text] distances. It is shown that if Fermi resonance is the sole cause of the complexity of the stretching absorptions, then these centroids represent the ν(NH) and ν(ND) frequencies unperturbed by Fermi resonance. The centroid frequencies in the three halides are unusually low, pointing to strong [Formula: see text] hydrogen bonding.

Synthese und Kristallstrukturbestimmung von Additionsverbindungen aus Alkyldimethylbromsilanen und N-Trimethylsilylimidazol/Syntheses and Crystal Structure Determination of Addition Compounds of Alkyldimethylbromosilanes and N-Trimethylsilylimidazole

1997 ◽  
Vol 52 (12) ◽  
pp. 1491-1496 ◽  
Author(s):  
Karl Hensen ◽  
Frank Gebhardta ◽  
Michael Bolteb
Keyword(s):  
Crystal Structure ◽  
Single Crystals ◽  
Structure Determination ◽  
Room Temperature ◽  
Crystal Structure Determination

Abstract The bromosilanes RMe2SiBr (R = Me, Et, n-Pr and i-Pr) form ionic 1:1-compounds with N-trimethylsilylimidazole (NTMSI), stable at room temperature. Crystals of the compounds with R = Et, n-Pr and i-Pr are obtained by sublimation. From the product of the reaction of 1,1-dibromosilacyclopentane with NTMSI single crystals of N,N′-bis(trimethylsilyl)imidazolium-bromide (R = Me) were obtained. In the new adducts both silicon atoms are tetracoordinated.

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