Combined single-crystal X-ray and neutron powder diffraction structure analysis exemplified through full structure determinations of framework and layer beryllate minerals

2010 ◽  
Vol 95 (4) ◽  
pp. 519-526 ◽  
Author(s):  
J. A. Armstrong ◽  
H. Friis ◽  
A. Lieb ◽  
A. A. Finch ◽  
M. T. Weller
Keyword(s):  
Single Crystal ◽  
Structure Analysis ◽  
Powder Diffraction ◽  
Neutron Powder Diffraction ◽  
X Ray ◽  
Diffraction Structure ◽  
Structure Determinations ◽  
Full Structure

On the Reaction of ortho-Diphenoquinone Valence Isomers with Primary and Secondary Amines. X-Ray Structure Analysis of a 2,3-Dihydro-1H-azepinone and its Photochemical and Oxidative Conversion Products

1979 ◽  
Vol 32 (9) ◽  
pp. 1931 ◽  
Author(s):  
H Becker ◽  
K Gustafsson ◽  
CL Raston ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Secondary Amines ◽  
Reaction Products ◽  
Oxidative Conversion ◽  
X Ray Diffraction ◽  
X Ray ◽  
Primary And Secondary Amines ◽  
Diffraction Structure ◽  
Structure Determinations ◽  
Photochemical Isomerization

Single-crystal X-ray diffraction structure determinations are reported for three reaction products and photoisomers formed from reactions between an o-diphenoquinone valence isomer and primary and secondary amines, namely: 3,5-di-t-butyl-7-(3,5-di-t-butyl-2-hydroxyphenyl)-1-methyl-2,3-dihydro-1H-azepin-2-one (8; R1 = R2 = But, R3 = Me), its photochemical isomerization product 4,6-di-t-butyl-1-(3,5-di-t-butyl-2-hydroxyphenyl)-2-methyl-2-azabicyclo[3,2,0]hept-6-en-3-one (9; R1 = R2 = But, R3 = Me) and 4',5,7-tri-t-butyl-3'-(2,2-dimethylpropionyl)-1'-methylspiro[benzofuran-3(2H)-2'- pyrrolidinel-2,5'-dione (12; R1 = R2 = But, R3 = Me).

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.

Metastable β-phase of benzophenone: independent structure determinations via X-ray powder diffraction and single crystal studies

2000 ◽  
Vol 56 (3) ◽  
pp. 486-496 ◽  
Author(s):  
Hartmut Kutzke ◽  
Helmut Klapper ◽  
Robert B. Hammond ◽  
Kevin J. Roberts
Keyword(s):  
Single Crystal ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Metastable Phase ◽  
Search Space ◽  
Powder Diffraction Data ◽  
Space Group ◽  
X Ray ◽  
Β Phase ◽  
Structure Determinations

Benzophenone was the first organic molecular material to be identified as polymorphic. It is well known that benzophenone crystallizes in a stable orthorhombic α-form (m.p. 321 K) with space group P212121 and a = 10.28, b = 12.12, c = 7.99 Å, [Girdwood (1998). Ph.D. thesis. Strathclyde University, Glasgow, Scotland]. Here we report two separate structure determinations of the metastable β-form (m.p. 297–299 K). Crystalline material of the metastable polymorph was obtained from a melt supercooled to ∼243 K. The structure was determined from X-ray powder diffraction data by employing a novel, computational systematic search procedure to identify trial packing arrangements for subsequent refinement. Unit-cell and space-group information, determined from indexing the powder diffraction data, was used to define the search space. The structure was also determined from single-crystal diffraction data at room temperature and at 223 K. The metastable phase is monoclinic with space group C2/c and a = 16.22, b = 8.15, c = 16.33 Å, β = 112.91° (at 223 K). The structures derived from the individual techniques are qualitatively the same. They are compared both with each other and with the stable polymorph and other benzophenone derivatives.

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