MicroED (microcrystal electron diffraction) is emerging as a powerful technique for the structural elucidation of challenging compounds as it bypasses the main limitation of growing crystals of suitable size for single-crystal X-ray diffraction. Over the past two decades, Electron Diffractometry (microED, 3DED) has undergone a significant transformation, from a technique managed by only a handful of enthusiasts into a new standard method. With state-of-the-art fully automated electron diffractometers crystal structure determination is nowadays as straightforward as it is known from its larger brother, single crystal X-ray crystallography. However, the notable distinction to the latter lies in the size of the crystals used for single crystal electron diffractometry, which is typically in the range between 50 nm to 1 μm. This feature makes Electron Diffractometry particularly interesting for research on materials where larger crystals are either unavailable or inaccessible within a reasonable timeframe. Applications range from natural products and pharmacology to geological sciences, advanced materials, nanotechnology, MoF and many more. MicroED is also merging in the crystallographic community [1] due to its incredible advantages that combine X-Ray benefits with Electron Microscopy. By combining the imaging features with the diffraction mode of an electron diffractometer it is possible to acquire imaging and diffraction from the same sample, providing a variety of information on the individual crystals. Thus, crystals from what traditionally would have been considered as powder samples by x-ray standards can now be handled as single crystals by electron diffraction. This results in the unique advantage of studying multiple phases separately within the same sample. Electron Diffraction opens new innovative applications for people working in the industry and academic world for applications like imupurity profiling, detecting micro crystallinity in amorphous materials, assisted solid state screening, which no other technology can do at this moment as swift and accurate.
In this seminar Dr. Alessia Portieri and Dr. Laura Samperisi from ELDICO Scientific AG, Switzerland, will show a range of examples including both nanocrystalline samples of known MoFs and new materials, all measured in continuous rotation mode on a dedicated electron diffractometer. and the identification of changes of the structures by solvent removal from the pores. The results illustrate the potential of this technique in the field of porous coordination networks and the benefits of dedicated instrumentation that has become available in recent years. They will also be sharing some different case studies with new applications using electron diffraction for people working in the pharmaceutical and related industry or academia.
[1] Gemmi, M., Mugnaioli, E., Gorelik, T. E., Kolb, U., Palatinus, L., Boullay, P., Hovmöller, S. & Abrahams, J. P. (2019). ACS Cent. Sci., 5, 1315.