scholarly journals Observation of Dual Room Temperature Fluorescence–Phosphorescence in Air, in the Crystal Form of a Thianthrene Derivative

2018 ◽  
Vol 122 (43) ◽  
pp. 24958-24966 ◽  
Author(s):  
Piotr Pander ◽  
Agnieszka Swist ◽  
Roman Turczyn ◽  
Stephanie Pouget ◽  
David Djurado ◽  
...  
Keyword(s):  
Room Temperature ◽  
Crystal Form

scholarly journals Room-temperature spin nutations in a magnetically condensed phase of [Y(pc)2]•

2021 ◽  
Author(s):  
Athanassios Boudalis ◽  
Jorge Enrique Olivares Peña ◽  
Eufemio Moreno Pineda ◽  
Artem Fediai ◽  
Wolfgang Wenzel ◽  
...  
Keyword(s):  
Liquid Helium ◽  
Condensed Phase ◽  
Room Temperature ◽  
Crystal Form ◽  
Temperature Liquid

FID-detected nutations of the antiferromagnetic crystal form of [Y(pc)2]• demonstrated that its radical spin can be coherently driven in the its magnetically condensed undeuterated phase and at room temperature. Liquid-helium...

scholarly journals EFFECT OF ETHANOL-WATER COMPOSITION ON CLINDAMYCIN HYDROCHLORIDE PSEUDOPOLYMORPHISM

2016 ◽  
Vol 8 (11) ◽  
pp. 269 ◽  
Author(s):  
Ilma Nugrahani ◽  
Silvana Anggraeni
Keyword(s):  
Room Temperature ◽  
Crystal Form ◽  
Recrystallization Process ◽  
Polarization Microscopy ◽  
X Ray ◽  
Water Composition ◽  
Infra Red ◽  
Long Time ◽  
Ethanol In Water ◽  
Original Crystal

Objective: Formation of clindamycin hydrochloride (clindamycin HCl) in monohydrate-ethanolate from the recrystallization process with ethanol–water (5:2) has been reported a long time ago. However, the effect of ethanol-water compositions into pseudo-polymorphism formation and its stability of was not reported yet. This study aimed to investigate the effect of ethanol-water proportion on the formation of clindamycin HCl-monohydrate and its ethanol solvate.Methods: Clindamycin HCl was recrystallized with the various percentages of ethanol. The fresh and after storage for 24 h at humidity and room temperature (25±2 °C, RH: 70±1%) crystals were characterized by FTIR (Fourier transform infra-red), PXRD (powder x-ray diffractometer), and DTA (differential scanning calorimeter). The study of desolvation/dehydration then was observed with a polarization microscopy-plate heater.Results: The results showed that monohydrate crystal was obtained from recrystallization in a concentration less than 50% ethanol in water. Next, the ethanolate was produced from the solvent of>70% ethanol. Meanwhile, the 50–70 % ethanol produced a hydrate–ethanolate, crystal, which has both hydrate and ethanol in its lattice. This hydrate-ethanolates was unstable, even in ambient temperature.Conclusion: Concentration of ethanol in water as the solvent will determine the clindamycin HCl pseudo polymorphism, which will back to its original crystal form by the time of storage.

The mechanical behaviour of single crystals of certain face-centred cubic metals

1951 ◽  
Vol 244 (880) ◽  
pp. 177-203 ◽  
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Room Temperature ◽  
Critical Shear Stress ◽  
Crystal Form ◽  
Surface Contamination ◽  
Cube Root ◽  
Impurity Atoms ◽  
Gold Silver ◽  
Normal Diffusion

Single crystal rods of gold, silver and nickel have been prepared from the melt by a modified cooling method. The three metals differ in that the gold is very pure and has no surface contamination; the silver is very pure and the surface normally shows contamination; the nickel is markedly less pure. These three features find expression in the results. The stress-glide relationship has been investigated over the whole range to fracture, special attention being paid to the region of small glide. At very small glides the results show certain variations attributed to metastable conditions. For pure metals at low temperatures a region of easy glide has been established, which is absent in nickel. Considerations of the variation of hardening with temperature at constant glide show that, at moderate glide, rise of temperature at low temperature promotes hardening, but rise of temperature at high temperature leads to decrease of hardening. From these results it is concluded that in metals without notable impurity glide is due to two distinct processes, first the initiation of glide planes, which temperature agitation tends to check, and secondly to glide proceeding on planes already initiated, which temperature agitation tends to promote. The surface contamination of silver single crystals which takes place by exposure to air at room temperature raises the critical shear stress somewhat, but has a much more marked effect on the hardening after some tens of per cent of glide has taken place, which is attributed to diffusion of the impurity atoms, probably oxygen, taking place during the travel of the dislocations. This is distinct from normal diffusion, which is negligible at room temperature. The results on the effect of surface contamination explain abnormalities previously noted with silver. The close connexion of asterism and hardening is exhibited in the results obtained with gold and silver. In particular, silver in the region of easy glide shows very small asterism, even at large glide. The cube root of the breaking stress of all metals in single-crystal form has been found to show a linear relationship with temperature.

Preparation and Characterization of Well-Dispersed Nd1.6Eu0.4Zr2O7 Solid Solution and its Fluorescent Behavior

2010 ◽  
Vol 97-101 ◽  
pp. 182-186
Author(s):  
Yu Ping Tong ◽  
Jing Wang ◽  
Rui Zhu Zhang ◽  
Shun Bo Zhao
Keyword(s):  
Solid Solution ◽  
Solid Solutions ◽  
Room Temperature ◽  
Single Phase ◽  
Combustion Process ◽  
Crystal Form ◽  
Scherrer Formula ◽  
Xrd Patterns ◽  
Average Size

Well-dispersed Nd1.6Eu0.4Zr2O7 solid solutions were successfully prepared by a convenient salt-assisted combustion process using glycine as fuel. The samples were characterized by XRD, Raman, TEM and HRTEM. The results showed that the Nd ion can be partially replaced by Eu ion. The substituted product was still single-phase solid solutions and the crystal form remained unchanged. TEM images showed that the Nd1.6Eu0.4Zr2O7 solid solutions were composed of well-dispersed sphere-shaped nanocrystals with an average size of 30 nm, which is consistent with the value obtained from XRD patterns using the Scherrer formula. Moreover, the fluorescent characterization of the Nd1.6Eu0.4Zr2O7 nanocrystals at 385 nm upon excitation was carried out at room temperature, and the results showed that there were some intense and prevailing emission peaks located at 590-650 nm.

Temperature-resolved study of the structural behaviour of nickel octahexyl phthalocyanine up to the liquid crystal transition

2003 ◽  
Vol 59 (5) ◽  
pp. 617-624 ◽  
Author(s):  
Madeleine Helliwell ◽  
Simon J. Teat ◽  
Simon J. Coles ◽  
William Reeve
Keyword(s):  
Crystal Structure ◽  
Differential Scanning Calorimetry ◽  
Room Temperature ◽  
Crystal Form ◽  
Crystallographic Investigation ◽  
Structural Behaviour ◽  
Scanning Calorimetry ◽  
Dsc Measurements ◽  
Structure Determinations ◽  
Crystal Transition

This paper describes a temperature-resolved crystallographic investigation into the behaviour of the title compound as the temperature is increased stepwise from room temperature up to 418 K, which is the temperature at which a transition to a discotic columnar mesophase takes place. The experiments were conducted using synchrotron radiation on Station 9.8 at the SRS at the Daresbury Laboratory. An intermediate transition to a less well ordered crystal form was seen at 326 K and differential scanning calorimetry (DSC) measurements confirmed the transition temperature of this change. Also, a new improved room-temperature crystal structure was obtained, as well as further structure determinations at 323, 328 and 353 K. These showed that as the mobility, particularly of the hexyl groups, increases with temperature, the packing of the molecules adjusts from pseudohexagonal layers to a rectangular arrangement.

scholarly journals A new crystal form of human acetylcholinesterase for exploratory room-temperature crystallography studies

2019 ◽  
Vol 309 ◽  
pp. 108698 ◽  
Author(s):  
Oksana Gerlits ◽  
Kwok-Yiu Ho ◽  
Xiaolin Cheng ◽  
Donald Blumenthal ◽  
Palmer Taylor ◽  
...  
Keyword(s):  
Room Temperature ◽  
Crystal Form

scholarly journals Preparation and Characterization of [C6H5CH2 NH3]2PbI4, [C6H5CH2CH2SC(NH2)2]3 PbI5 and [C10H7CH2NH3]PbI3 Organic-Inorganic Hybrid Compounds

1999 ◽  
Vol 54 (11) ◽  
pp. 1405-1409 ◽  
Author(s):  
G. C. Papavassiliou ◽  
G. A. Mousdis ◽  
C. P. Raptopoulou ◽  
A. Terzis
Keyword(s):  
Optical Absorption ◽  
Room Temperature ◽  
Crystal Form ◽  
Optical Absorption Spectra ◽  
Photoluminescence Spectra ◽  
Inorganic Hybrid ◽  
Hybrid Compounds ◽  
Excitonic Interactions ◽  
Low Dimensional

The preparation, crystal structures, optical absorption spectra, and photoluminescence spectra of the title compounds are reported. The compounds were prepared in single crystal form. [C6H5CH2NH3]2PbI4 consists of anionic perovskite sheets of corner-sharing Pbl6 octahedra, which alternate with the C6H5CH2NH3+ sheets. [ C6H5CH2CH2SC(NH2)2]3 PbI5 consists of zig-zag chains of anionic corner sharing PbI6 octahedra separated by C6H5CH2CH2SC(NH2)2 cations. [C10H7CH2NH3]Pbl3 consists of twin chains of edge-sharing PbI6 octahedra separated by C10H7CH2NH3 cations. The compounds are thus low-dimensional systems. The excitonic spectra were observed in all cases, even at room temperature, and the possibility of organicinorganic excitonic interactions is discussed.

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