It is well known that medium sized crystal structures (number of atoms > 100) are still hard to solve by single-crystal diffraction techniques. It is expected that, due to the increasing size of the supramolecular systems under study and the poor crystallinity of assemblies held together by non-covalent interactions, there is a need for more powerful techniques and methods for structure determination. In our group there is a significant expertise in method development (see also DIRDIF and CRUNCH).
The use of modern X-ray equipment (access to CCD diffractometers etc.) and new
improved structure solution methods will be essential for studying modern chemical compounds.
One- and two-dimensional periodicity of compounds can succesfully be studied by
Insight in one- or two-dimensional periodicity provides useful information about
preferred orientation and stacking of molecules which, although no
three-dimensional structure is available, may yield essential information about
However, the periodicity of supramolecular systems (large
d-spacings) and its temperature dependency (e.g. in liquid crystals) needs
state-of-the-art equipment and methods. We believe that application of modern
powder-diffraction techniques is essential for studying supramolecular
assemblies and that development in this direction is needed.
Recently, an advanced new X-ray diffraction facility, a D8 Advance with hot humidity stage and Vantec detector, was installed in Nijmegen. This new facility is certainly a step into the field of modern chemical crystallography!