March 2011 – Chemical Crystallography

An Engagement with X-rays

Mar 302011

Not content with showing off the eye-catching brilliance of her new diamond engagement ring, final year Inorganic Chemistry student Rowena Scott wanted to reveal the beautiful symmetry of its atomic structure. She recorded an X-ray diffraction pattern from the diamond using one of the Chemistry Department’s new state of the art, SuperNova dual source X‑ray diffractometers.

Rowena’s current research project with Dr Simon Clarke involves the synthesis of iron chalcogenide superconductors. The structures of these materials are then determined using single crystal X-ray diffraction techniques.

Chemical Crystallography Service manager, Dr Amber Thompson said “We see a wide range of materials of varying crystallinity from many research groups in the Department of Chemistry, usually grown at the bottom of glass schlenks or flasks; it’s not often that such a lovely crystal turns up mounted in a band of gold”.

$Diffraction pattern of the diamond$ The diffracted X-rays were measured while rotating the diamond in an X-ray beam. The resulting diffraction pattern shows the position and intensity of the beams diffracted by the organised structure of carbon atoms in the crystal. The white rings overlaid on the image indicate the angles at which diamond peaks are expected to occur, which agree with the collected data.

Diamond diffracts X-rays so efficiently that the X-ray generator had to be run at 10% of its usual power in order to avoid overloading the X-ray detector.

Prof. Andrew L. Goodwin

Mar 172011

Andrew and his research group are close associates of Chem. Cryst.. We share group meetings and, although they have some very strange ideas about what constitutes a single crystal, they collect data in the lab.

For more information, see their webpage.

Prof. C. Keith Prout (1934-2007)

Mar 172011

Keith Prout died quite suddenly in September 2007 after a short illness.

Although he had been officially retired for several years, he was continuing an active research program with Nick Rees combining X-ray and NMR studies. X-ray structure analysis gives information about disorder and thermal vibrations in crystals. When combined with solid state NMR a complete dynamic profile of the crystal can be obtained.

Previous studies of penicillins, ansa-titanocenes and tri-ethyl phosphate molecular complexes with various hosts suggest a variety of molecular motions in addition to the ‘translation-libration-screw’ motion derived from the crystallographic atomic displacement parameters. He also studied order/disorder phase transitions, molecular motion and chiral selectivity in deoxycholic acid molecular complexes.

Dr. James Haestier

Mar 172011

James is mathematician by training, who became a a particle physicist and now applies his skills to understanding some of the problems associated with errors in least-squares refinement. He is working on programming an error analysis library.

Dr. Mustapha Sadki

Mar 172011

Mustapha is a Senior Research Associate in the group and is a highly experienced and efficient programmer. His specialism is C++ and he is responsible for the Small Molecule ToolKit, SMTK.

Dr. Violeta Jevtovic

Mar 162011

Violeta is an assistant professor in the Chemistry Department at the University of Novi Sad, Serbia. She obtained her Ph.D. in coordination chemistry studying the synthesis, structure and biological activity of transition metal compounds and visited for a few months to learn more about crystallography.

Prof. B. Terrence (Terry) M. Willis

Mar 162011

Terry worked for the Atomic Energy Research Establishment, Harwell for many years before he joined Chem. Cryst.

Terry was one of the pioneers of the use of neutron scattering in the United Kingdom and a founder member of the BCA. Although interested in many areas of crystallography, his particular specialities are neutron scattering studies of crystal structures and lattice dynamics of inorganic materials. Recent interests are the determination of the crystal structures of the oxides of uranium and the nature of the phase transitions in U4O9. The oxide studies are undertaken in collaboration with Frederico Garrido of the University of Paris, Lech Nowicki of the Soltan Institute of Nuclear Physics, Warsaw and Alberto Albinati of the University of Milan.

The author of a number of highly regarded books, there is a prize awarded in his honour sponsored by the Institute of Physics and the Royal Society of Chemistry.

Mr. Karim J. Sutton

Mar 162011

Karim carried out a systematic study of ion binding in rotaxanes in collaboration with Paul Beer’s research group. He has since returned to Chem Cryst to undertake a DPhil. project under the supervision of Dr. Richard Cooper.

Miss Emma J. McKinley

Mar 162011

Emma’s research is focussed on developing a better understanding of the solid state. She is using a three pronged attack, studying the crystallisation of chalcones; examining the effect of temperature on a material that undergoes a phase transition, and investigating the World’s Favourite Space Group, P2₁/c. She is using a wide range of probes, including the Cambridge Structural Database, dSNAP, Laue Diffraction, Solid State NMR and Variable Temperature Single Crystal Diffraction as well as collecting data at Diamond. When not fighting to grow crystals or preparing dinner for the team at Diamond, she enjoys dancing, but refuses to perform for the group.

Mr. Jeremy P. Law

Mar 162011

Jeremy’s research revolves around using various techniques (NMR, crystallography and DFT calculations) to provide information about exactly where hydrogen atoms are located in crystal structures, and exploring the merits and shortcomings of the various techniques for this purpose. When he isn’t trying to persuade a supercomputer to calculate what he wants, he enjoys playing the trumpet with the Oxford University Big Band, plays squash and designs prize-winning posters.

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