Jul 292010
 

The ACA was held at the Sheraton Hotel in Chicago, IL.  Contributions from Chem. Cryst. include:

James Haestier, Amber L. Thompson, David J. Watkin, George C. Feast, Jeremy Robertson & Lee Page
Why is P21/n a Standard Non-Standard Space Group? (Poster)

Amber L. Thompson & David J. Watkin
Unpublishable” Data:  Does My R-factor Read the rest

Jul 132010
 

Cryst. Rev. (2010), 16(3), 197-230.    [ doi:10.1080/08893110903483246 ]

X-ray single crystal structure analysis has become a gold standard for the determination of molecular geometry. The reliability of the technique is a triumph for science and technology working together. The uniqueness of well-crystalline material intrigued early natural philosophers, and their examinations, followed by the discovery … Read the rest

Jun 292010
 
CRYSTALS Enhancements: Dealing with Hydrogen Atoms in Refinement (R. I. Cooper, A. L. Thompson and D. J. Watkin)

J. Appl. Cryst. (2010), 43, 1100-1107.    [ doi:10.1107/S0021889810025598 ]

Because they scatter X-rays weakly, H atoms are often abused or neglected during structure refinement. The reasons why the H atoms should be included in the refinement and some of the consequences of mistreatment are discussed along with selected real examples demonstrating some of the … Read the rest

Apr 152010
 

Cryst. Rev. (2010), 16(2), 133-144.    [ doi:10.1080/08893110903483238 ]

Recent developments in crystallographic error analysis are described. This report provides an introduction to more-formal work, originally published in Ref. (Haestier, J., J. Appl. Cryst. 2009, 42, 798). Prior to the main discussion, a brief overview of the normal distribution and error-propagation is … Read the rest

Apr 152010
 
BCA Spring Meeting 2010

Susan Huth presents Kirsten Christensen with the Durward Cruickshank Award

The final dinner of the British Crystallographic Association Spring Meeting in Warwick was interrupted, as always, with the prize winning awards. Amber Thompson was awarded the International Union of Crystallography Prize (a copy of International Tables) for her explanation of the advantages of choosing non-standard Read the rest

Nov 182009
 

Acta Cryst. (2009), C65, o635-o638.    [ doi:10.1107/S0108270109046952 ]

The unusual methylene aziridine 6-tert-butyl-3-oxa-2-thia-1-azabicyclo[5.1.0]oct-6-ene 2,2-dioxide, C9H15NO3S, was found to crystallize with two molecules in the asymmetric unit. The structure was solved in both the approximately orthogonal and the oblique settings of space group No. 14, viz. Read the rest

Oct 302009
 
Synthesis and Structural Studies of Gallium(III) and Indium(III) Complexes of 2-acetylpyridine Thiosemicarbazones (J. Chan, A. L. Thompson, M. W. Jones, J. M. Peach)

Inorg. Chim. Acta  (2010), 363(6), 1140-1149.    [ doi:10.1016/j.ica.2009.10.020 ]

Four 2-acetylpyridine 4N-alkyl thiosemicarbazones, and their Ga(III) and In(III) complexes have been prepared and characterised by fluorescence, UV–Vis, IR, 1H and 13C NMR spectroscopy, mass spectrometry and X-ray crystallographic analysis. Comparison of the crystal structures gave an insight into the nature of … Read the rest

Oct 222009
 

Acta Cryst. (2009), E65, o2904-o2905.    [ doi:10.1107/S1600536809043827 ]

X-ray crystallographic analysis of the title hydrobromide salt, C10H20N+Br-, of (1R,2S,3R,5R,8aR)-3-hydroxymethyl-5- methyloctahydroindolizine-1,2-diol defines the absolute and relative stereochemistry at the five chiral centres in steviamine, a new class of polyhydroxylated indolizidine alkaloid isolated from Stevia rebaudiana (Asteraceae) leaves.

Electronic reprint:

Read the rest
Aug 212009
 

The 25th European Crystallographic Meeting was held in the Harbiye Museum and Cultural Centre in the beautiful city of Istanbul.  It was a very eventful week, and contributions to the conference made by Chem. Cryst. include:

N. David Brown, James Haestier, Mustapha Sadki, Amber L. Thompson & David J. Watkin
A Further Improved Structure Matching Read the rest

Aug 012009
 

J. Appl. Cryst. (2009), 42, 798-809.    [ doi:10.1107/S0021889809024376 ]

A new method is presented for handling errors on crystallographic data. In single-crystal diffraction experiments, two variance-covariance matrices are present, one for the cell parameters and the second for the refined parameters (atomic coordinates and anisotropic displacement parameters). These two matrices can be combined so … Read the rest