X-ray structure of the dipotassium salt of d-mannose 1-phosphate 3.25 hydrate

2005 ◽  
Vol 340 (15) ◽  
pp. 2422-2427 ◽  
Author(s):  
Lucjan B. Jerzykiewicz ◽  
Tadeusz Lis ◽  
Ewa Zuziak
Keyword(s):  
X Ray ◽  
Dipotassium Salt

Preparation, characterization, and structure of two dipyrrolide thorium homoleptic complexes — Isolation of a dipyrrolide dipotassium salt with an inverted-sandwich type of structure

2005 ◽  
Vol 83 (6-7) ◽  
pp. 832-837 ◽  
Author(s):  
Arunachalampillai Athimoolam ◽  
Sandro Gambarotta ◽  
Ilia Korobkov
Keyword(s):  
Solid State ◽  
Diffraction Analysis ◽  
Key Words ◽  
X Ray Diffraction ◽  
Potassium Salts ◽  
Polymeric Structure ◽  
X Ray ◽  
Dipotassium Salt ◽  
Sandwich Type

Reactions of the in-situ-generated potassium salts of the dipyrroles (C4H3NH)2C(CH3)2 and of (C4H3NH)2C(CH3)(C6H5) with ThCl4(DME)2 has afforded the corresponding homoleptic ({[(C4H3N)2C(CH3)2]3Th}[K2(DME)])n (1) and {[(C4H3N)2C(CH3)(C6H5)]3Th}[K2(DME)] (2). In the case of 1, the solid state polymeric structure was elucidated by X-ray diffraction analysis. Preliminary attempts to reduce these species have so far afforded only intractable materials. Just in the case of 2, it was possible to isolate the corresponding ligand dipotassium salt {(C4H3NH)2C(CH3)(C6H5)[K(DME)]2}n (3) as the only characterizable material. This species possesses an unprecedented inversed-sandwich type of structure. Key words: thorium, homoleptic, dipyrrolide.

Unique Coordination Mode of Potassium Ions to Glycyrrhizin: X-ray Crystal Structure of Glycyrrhizin Dipotassium Salt

2009 ◽  
Vol 38 (11) ◽  
pp. 1024-1025 ◽  
Author(s):  
Yasuko In ◽  
Masaru Uchida ◽  
Masamichi Watanabe ◽  
Norio Aimi ◽  
Toshimasa Ishida
Keyword(s):  
Crystal Structure ◽  
Coordination Mode ◽  
Potassium Ions ◽  
X Ray ◽  
Dipotassium Salt

scholarly journals Organotrifluoroborates as attractive self-assembling systems: the case of bifunctional dipotassium phenylene-1,4-bis(trifluoroborate)

2015 ◽  
Vol 44 (45) ◽  
pp. 19447-19450 ◽  
Author(s):  
Aurelia Falcicchio ◽  
Sten O. Nilsson Lill ◽  
Filippo M. Perna ◽  
Antonio Salomone ◽  
Donato I. Coppi ◽  
...  
Keyword(s):  
Computational Chemistry ◽  
Self Assembly ◽  
X Ray ◽  
Dipotassium Salt ◽  
X Ray Crystallography ◽  
Self Assembling ◽  
Non Covalent Interactions ◽  
Covalent Interactions

A multitude of non-covalent interactions, investigated by X-ray crystallography and computational chemistry techniques, proved to be responsible of the spontaneous self-assembly of a bis(trifluoroborate) dipotassium salt.

Dianion eines Methylendiborirans, Synthese seiner Alkali- und Magnesiumsalze und Struktur seines Dikaliumsalzes / Dianion of a Methylenediborirane, Synthesis of its Alkali and Magnesium Salts and Structure of its Dipotassium Salt

1988 ◽  
Vol 43 (7) ◽  
pp. 801-806 ◽  
Author(s):  
Harald Meyer ◽  
Günter Schmidt-Lukasch ◽  
Gerhard Baum ◽  
Werner Massa ◽  
Armin Berndt
Keyword(s):  
Nmr Spectroscopy ◽  
Structure Analysis ◽  
Potassium Salt ◽  
Infinite Chain ◽  
Potassium Ions ◽  
Sodium Potassium ◽  
X Ray ◽  
Dipotassium Salt ◽  
Tert Butyl ◽  
Magnesium Salts

Lithium, sodium, potassium, caesium and magnesium salts of the dianion of 1,2-di-tert-butyl-3- [bis(trimethylsilyl)methylene]-1,2-diborirane have been synthesized and charactarized by 13C and 11B NMR spectroscopy. X-ray structure analysis of the di-potassium salt proves cyclic derealization of two. π-electrons in the CB2-ring by short C-B (150 pm) and B -B (158 pm) bonds. The exocyclic C-C bond (150 pm) is bridged by two potassium ions. One of them contacts the boron atoms of a neighbouring dianion leading to a helicoidal infinite chain with 41-symmetry along the c direction.

Space and Time Distribution of Hard X-Ray Emission in a Loop at the Beginning of a Flare

1994 ◽  
Vol 144 ◽  
pp. 275-277
Author(s):  
M. Karlický ◽  
J. C. Hénoux
Keyword(s):  
Time Distribution ◽  
Electron Bombardment ◽  
Spatial Evolution ◽  
Superthermal Electrons ◽  
Flare Loop ◽  
X Ray ◽  
Superthermal Electron ◽  
Flare Loops ◽  
Chromospheric Evaporation ◽  
Temporal And Spatial

AbstractUsing a new ID hybrid model of the electron bombardment in flare loops, we study not only the evolution of densities, plasma velocities and temperatures in the loop, but also the temporal and spatial evolution of hard X-ray emission. In the present paper a continuous bombardment by electrons isotropically accelerated at the top of flare loop with a power-law injection distribution function is considered. The computations include the effects of the return-current that reduces significantly the depth of the chromospheric layer which is evaporated. The present modelling is made with superthermal electron parameters corresponding to the classical resistivity regime for an input energy flux of superthermal electrons of 109erg cm−2s−1. It was found that due to the electron bombardment the two chromospheric evaporation waves are generated at both feet of the loop and they propagate up to the top, where they collide and cause temporary density and hard X-ray enhancements.

Some Problems in Understanding the Solar Corona

1994 ◽  
Vol 144 ◽  
pp. 1-9
Author(s):  
A. H. Gabriel
Keyword(s):  
Solar Corona ◽  
Solar Atmosphere ◽  
Theoretical Modelling ◽  
Total System ◽  
Major Advance ◽  
X Ray ◽  
Proper Perspective ◽  
Space Observations

The development of the physics of the solar atmosphere during the last 50 years has been greatly influenced by the increasing capability of observations made from space. Access to images and spectra of the hotter plasma in the UV, XUV and X-ray regions provided a major advance over the few coronal forbidden lines seen in the visible and enabled the cooler chromospheric and photospheric plasma to be seen in its proper perspective, as part of a total system. In this way space observations have stimulated new and important advances, not only in space but also in ground-based observations and theoretical modelling, so that today we find a well-balanced harmony between the three techniques.

White-Light Coronal Structures: Streamers and CMEs

1994 ◽  
Vol 144 ◽  
pp. 82
Author(s):  
E. Hildner
Keyword(s):  
Emission Line ◽  
Electron Density ◽  
White Light ◽  
Coronal Mass Ejections ◽  
X Rays ◽  
Solar Cycles ◽  
Temperature Function ◽  
X Ray ◽  
Eclipse Observations ◽  
Coronal Structures

AbstractOver the last twenty years, orbiting coronagraphs have vastly increased the amount of observational material for the whitelight corona. Spanning almost two solar cycles, and augmented by ground-based K-coronameter, emission-line, and eclipse observations, these data allow us to assess,inter alia: the typical and atypical behavior of the corona; how the corona evolves on time scales from minutes to a decade; and (in some respects) the relation between photospheric, coronal, and interplanetary features. This talk will review recent results on these three topics. A remark or two will attempt to relate the whitelight corona between 1.5 and 6 R⊙to the corona seen at lower altitudes in soft X-rays (e.g., with Yohkoh). The whitelight emission depends only on integrated electron density independent of temperature, whereas the soft X-ray emission depends upon the integral of electron density squared times a temperature function. The properties of coronal mass ejections (CMEs) will be reviewed briefly and their relationships to other solar and interplanetary phenomena will be noted.

Iron K-Line Emission from X-Ray Binaries

1988 ◽  
Vol 102 ◽  
pp. 47-50
Author(s):  
K. Masai ◽  
S. Hayakawa ◽  
F. Nagase
Keyword(s):  
Accretion Disk ◽  
Radiative Recombination ◽  
Characteristic Temperature ◽  
Line Emission ◽  
Ionization Front ◽  
Continuum Radiation ◽  
X Ray ◽  
Low Mass ◽  
X Ray Binaries

AbstractEmission mechanisms of the iron Kα-lines in X-ray binaries are discussed in relation with the characteristic temperature Txof continuum radiation thereof. The 6.7 keV line is ascribed to radiative recombination followed by cascades in a corona of ∼ 100 eV formed above the accretion disk. This mechanism is attained for Tx≲ 10 keV as observed for low mass X-ray binaries. The 6.4 keV line observed for binary X-ray pulsars with Tx> 10 keV is likely due to fluorescence outside the He II ionization front.

Diagnostics of Gold Laser Plasmas

1988 ◽  
Vol 102 ◽  
pp. 357-360
Author(s):  
J.C. Gauthier ◽  
J.P. Geindre ◽  
P. Monier ◽  
C. Chenais-Popovics ◽  
N. Tragin ◽  
...  
Keyword(s):  
Experimental Results ◽  
Pure Gold ◽  
Electronic Temperature ◽  
X Ray ◽  
Laser Plasmas ◽  
Collisional Radiative Model ◽  
Radiative Model

AbstractIn order to achieve a nickel-like X ray laser scheme we need a tool to determine the parameters which characterise the high-Z plasma. The aim of this work is to study gold laser plasmas and to compare experimental results to a collisional-radiative model which describes nickel-like ions. The electronic temperature and density are measured by the emission of an aluminium tracer. They are compared to the predictions of the nickel-like model for pure gold. The results show that the density and temperature can be estimated in a pure gold plasma.

Axial Observation of X-Ray Spectra from a Beam-Foil Source

1988 ◽  
Vol 102 ◽  
pp. 339-342
Author(s):  
J.M. Laming ◽  
J.D. Silver ◽  
R. Barnsley ◽  
J. Dunn ◽  
K.D. Evans ◽  
...  
Keyword(s):  
Spectral Resolution ◽  
Heavy Ion ◽  
Ion Beams ◽  
Beam Axis ◽  
Doppler Broadening ◽  
X Ray ◽  
Beam Foil

AbstractNew observations of x-ray spectra from foil-excited heavy ion beams are reported. By observing the target in a direction along the beam axis, an improvement in spectral resolution, δλ/λ, by about a factor of two is achieved, due to the reduced Doppler broadening in this geometry.

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