Experimental Techniques

Crystallography is primarily an experimental technique.   Pushing the boundaries of what is currently practical is an important part of the development of our science.

• Exploiting Synchrotron Radiation

  The time allocated at Diamond (I19) to the Chemical Crystallography Service has really brought the power of synchrotron radiation to our attention.  We are actively engaged in a number of collaborative research projects with scientists at Diamond Light Source.  These include exploiting the tunability of synchrotron radiation and Karim Sutton is a joint student with his research focussed on harnessing variable wavelengths.  Other areas of interest are the effects of radiation on small molecule crystals and the study of complex diffraction phenomena.   Dr. Kirsten Christensen and Dr. Read more …

• The Boundary Between Diffuse Scattering and Modulation

  During crystallization a variety of different molecular interactions are at play, and they determine the final structure. These interactions are often competing, and depending on their mutual strengths, this can result in various degrees of order, that in turn can give rise to diffuse scattering or well-defined reflections in the diffraction pattern. It is important to investigate how order– part order –disorder affects the diffraction pattern and how this information can give us vital information concerning packing of molecules.  The balance between the interactions is very fine, and Read more …

• Structures from Liquids

  Crystallography is inherently a solid-state technique.  However, where a material is a liquid under ambient conditions, it may be possible either to grow a crystal at low temperature and mount it using cryo-techniques or, alternatively, grow a crystal in situ on the diffractometer.  In order to be successful, the material must crystallise.  If this is the case it is then sealed in a capillary and mounted on the diffractometer.  It is then cooled to form a microcrystalline powder which is then zone-heated to melt the smallest crystallites so Read more …

• Solid State NMR

  Although solid state NMR is outside our primary area of expertise, it is an invaluable tool that is complementary to diffraction techniques.  In addition to using solution NMR as a test for bulk purity (by comparison of the single crystal and bulk spectra) it can provide a unique understanding of the dynamics with in a system.

  We are also currently engaged in a project using NMR to probe the effectiveness of hydrogen location with diffraction techniques and Density Functional Theory (DFT).  As with all solid state NMR work, this Read more …