Gas Electron Diffraction and Small Molecule Structures Centre, Bielefeld (GED@BI)

• Applicant: Professor Dr. Norbert W. Mitzel
• Subject Area: Inorganic Molecular Chemistry - Synthesis and Characterisation ; Physical Chemistry of Molecules, Liquids and Interfaces, Biophysical Chemistry
• Term: from 2013 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 233477935

Accurate molecular structures are the key for understanding chemical reactivity and molecular properties. We propose to establish an international core facility (GED@BI) for structure determination of small molecules by two specialized techniques: gas electron diffraction (GED) and X-ray diffraction (XRD) of in-situ grown crystals. GED is the most powerful method for investigating free molecules, undistorted by intermolecular interactions. It is complementary to single-crystal XRD. XRD is the standard method for crystalline samples and can be extended to liquids or gases, if they are crystallized directly (in situ) on a diffractometer. In addition, XRD allows determining electron density distributions. The proposed methods are in many cases the only applicable to determine the structure of new compounds. They find applications in fundamental and applied chemical science, in particular to study weak inter- or intramolecular interactions, unusual bonding situations, conformational behaviour, cluster compounds and many more. Comparing gas and solid state structures provides information on structural consequences of intermolecular interactions. GED data also serve to validate or disprove quantum-chemical single-molecule calculations. The core facility GED@BI runs the most modern instrument for high-resolution GED worldwide and the only one in the EU. It is one of few places for XRD of in-situ grown crystals. It has a wide group of international users, guarantees sustainable operation of two important methods, secures further method development, education of young scientists, and will demonstrate successful management and financing concepts.

• DFG Programme: Core Facilities