Oxonitridosilicate chlorides—synthesis, single-crystal X-ray and neutron powder diffraction, chemical analysis and properties of Ln4[Si4O3+xN7−x]Cl1−xOx with Ln=Ce, Pr, Nd and x≈0.2

2005 ◽  
Vol 178 (4) ◽  
pp. 976-988 ◽  
Author(s):  
Alexandra Lieb ◽  
Mark T. Weller ◽  
Paul F. Henry ◽  
Rainer Niewa ◽  
Rainer Pöttgen ◽  
...  
Keyword(s):  
Chemical Analysis ◽  
Single Crystal ◽  
Powder Diffraction ◽  
Neutron Powder Diffraction ◽  
X Ray

Pseudomesolite is mesolite

1985 ◽  
Vol 49 (350) ◽  
pp. 103-105 ◽  
Author(s):  
Rab Nawaz ◽  
John F. Malone ◽  
Victor K. Din
Keyword(s):  
Chemical Analysis ◽  
Single Crystal ◽  
Diffraction Pattern ◽  
Powder Diffraction ◽  
Electron Microprobe ◽  
Microprobe Analysis ◽  
Electron Microprobe Analysis ◽  
X Ray ◽  
Unit Cells ◽  
Wet Chemical

AbstractPseudomesolite from Carlton Peak, described by Winchell (1900), is shown to be mesolite by means of chemical and X-ray data. A proposal to this effect has been accepted by the International Mineralogical Association's Commission on New Minerals and Mineral Names. Electron microprobe analysis revealed variations in the composition of pseudomesolite and showed the presence of faroelite. The X-ray powder diffraction pattern is similar to that of mesolite. Single-crystal Weissenberg photographs showed a twinning intergrowth which is explained by a 90° rotation of 50% of the unit cells about the c-axis, so that the a- and b-axes of rotated cells coincide with the b- and a-axes respectively of the unrotated cells. This twinning can not be detected optically. Mesolite has recently been proved to be orthorhombic, contrary to the long-held view that it is monoclinic.Pseudomesolite from Oregon is also shown to be mesolite by single crystal Weissenberg photographs. A wet chemical analysis shows this material to be extremely silica-rich.

Hydrogen atoms location in [Re4(µ3-H)4(CO)12] by joint X-ray single-crystal and neutron powder diffraction analysis

1997 ◽  
pp. 1903 ◽  
Author(s):  
Norberto Masciocchi ◽  
Angelo Sironi ◽  
Norberto Masciocchi ◽  
Giuseppe D’Alfonso ◽  
Winfried Kockelmann ◽  
...  
Keyword(s):  
Single Crystal ◽  
Diffraction Analysis ◽  
Powder Diffraction ◽  
Neutron Powder Diffraction ◽  
Hydrogen Atoms ◽  
X Ray

scholarly journals Single-crystal X-ray and neutron powder diffraction investigation of the phase transition in tetrachlorobenzene

2006 ◽  
Vol 62 (2) ◽  
pp. 287-295 ◽  
Author(s):  
Sarah A. Barnett ◽  
Charlotte K. Broder ◽  
Kenneth Shankland ◽  
William I. F. David ◽  
Richard M. Ibberson ◽  
...  
Keyword(s):  
Phase Transition ◽  
Single Crystal ◽  
Powder Diffraction ◽  
Structural Changes ◽  
Neutron Powder Diffraction ◽  
X Ray Diffraction ◽  
Polymorphic Phase Transition ◽  
X Ray ◽  
Apparent Loss ◽  
Two Phases

The polymorphic phase transition of 1,2,4,5-tetrachlorobenzene (TCB) has been investigated using neutron powder diffraction and single-crystal X-ray diffraction. The diffraction experiments show a reversible phase change that occurs as a function of temperature with no apparent loss of sample quality on transition between the two phases. Neutron powder diffraction gives detailed information on the molecular structural changes and lattice parameters from 2 K to room temperature. The structure of the low-temperature form has been elucidated for the first time using single-crystal X-ray diffraction. Comparison of the α and β structures show that they are both based on the same sheet motif, with the differences between the two being very subtle, except in terms of crystal symmetry. Detailed analysis of the structures revealed the changes required for inter-conversion. A computational polymorph search showed that these two sheet structures are more thermodynamically stable than alternative herringbone-type structures.

Préparation, Identification et Radiocristallographie d'un Hétérocycle Cétonique à Intérêt Médicinal: l'Isopropyl-3, phényl-2, diaza-1,3, one-5 bicyclo [3,3,0] octène-1

1990 ◽  
Vol 5 (1) ◽  
pp. 48-49
Author(s):  
Par Mme C. Caranoni ◽  
M.J.P. Reboul ◽  
Melle C. Soula
Keyword(s):  
Chemical Analysis ◽  
Single Crystal ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Monoclinic Space Group ◽  
Powder Diffraction Data ◽  
Single Crystal Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Better Than

AbstractThe heterocycle of a functionalized 2-imidazoline, C15N2OH18, was obtained by reaction when 2-bromo, 2-alkenoïc ketone was allowed to react with a monosubstituted benzamidine. The compound presents a R*R* configuration. X-ray powder diffraction data have been obtained from single multifaceted brown crystals prepared at 273 K in benzene with triethylamine as catalyst. Chemical analysis gives a purity better than 99%. This compound crystallizes in the monoclinic space group P21/c [14]. The cell parameters were determined by employing single-crystal diffraction methods (Bragg and precession patterns) and were refined from accurate powder diffractometer data recorded at T = 293 (1) K.

The Crystal Structure of Potassium Hydrogeniodate (V), KIO3•HIO3

1972 ◽  
Vol 50 (8) ◽  
pp. 1134-1143 ◽  
Author(s):  
G. Kemper ◽  
Aafje Vos ◽  
H. M. Rietveld
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Single Crystal ◽  
Powder Diffraction ◽  
Qualitative Agreement ◽  
Three Dimensional ◽  
Neutron Powder Diffraction ◽  
X Ray Diffraction ◽  
Good Qualitative Agreement ◽  
X Ray

The crystal structure of KIO3•HIO3 has been determined by three-dimensional single crystal X-ray diffraction and by neutron powder diffraction. The crystallographic data are a = 7.025(2), b = 8.206(2), c = 21.839(5) Å, β = 97.98(2)°, space group P21/c, Z = 8 units KIO3•HIO3. The residual [Formula: see text] was 0.048 for 7516 independent X-ray reflections measured on a three-circle diffractometer with Zr-filtered Mo radiation. The results of the present study show good qualitative agreement with the structure recently determined by Chan and Einstein (7). The HIO3 and [Formula: see text] groups are pyramidal, the I—O(H) bonds vary from 1.898 to 1.939(4) Å and the I—O bonds from 1.786 to 1.827(4) Å, these lengths are not corrected for the effects of thermal motion. Strong O—I … O interactions and electrostatic attractions between K+ and Oδ− give slabs of thickness [Formula: see text] The slabs are connected by hydrogen bonds of 2.710 and 2.694 Å.

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