Research

X-ray Crystallography

The Linden research group is interested in modelling the solid state structures of disordered molecular materials showing diffuse scattering, as well as in a broad range of questions in Chemical Crystallography.

The Determination of Disordered Crystal Structures from Diffuse Scattering
The aim of the work is (1) to further develop the tools for analyzing such scattering and (2) to investigate molecular materials with important properties. The research is intended to contribute readily accessible, methodological advances to a neglected and underdeveloped part of crystal structure analysis, which, unlike studies of ordered materials, is far from routine. The number of studies involving diffuse scattering from disordered molecular materials is very limited compared with that for ordered structures.
The modeling of the structures involves the use of computationally demanding genetic algorithms and Monte Carlo calculations. The measurement of diffuse diffraction data requires very bright light sources, such as those at the European Synchrotron Radiation Facility and the Institut Laue Langevin in Grenoble.

Solutions to problems of disorder in materials are of interest internationally in the chemical industry, as in the cases of the recently postulated second polymorph of Aspirin and Pigment Red, both of which are economically significant materials. They are also of interest locally, as one focus of research at the University of Zurich is to develop molecular materials with interesting solid state stereochemistry that sometimes requires advanced diffuse scattering models to resolve.

Chemical Crystallography
We have a general interest in molecular interactions and their relationship to structural properties. Single-crystal X-ray crystallography is used as the main investigative tool. Aspects of hydrogen bonding and how this drives the supramolecular and structural properties of materials is a key focus.

Mission

The X-ray Crystallography Facility and the Linden Research Group have the following primary goals:

  • To support the projects of the research groups in the Institute of Organic Chemistry by providing and maintaining a state-of-the-art small-molecule crystal structure determination facility, together with the associated expertise necessary for the efficient completion of analyses to a high standard.
  • To contribute readily accessible, methodological advances to the study of diffuse scattering, which is a quite non-routine aspect of crystal structure analysis.
  • To further the breadth and understanding of the structure and properties of molecular materials.
  • To ensure that skills and rigour in the art of crystal structure analyses are maintained through teaching of dedicated courses in the science.