Largest magnetic anisotropy of a molecule measured at BESSY II
THz-EPR setup in the experimental hall of BESSY II. © HZB
The magnetic properties of the investigated bismuth complex (center) were investigated using THz-EPR spectroscopy at BESSY II. The method uses electromagnetic radiation from the THz to the infrared range in combination with high magnetic fields. © HZB
At the Berlin synchrotron radiation source BESSY II, the largest magnetic anisotropy of a single molecule ever measured experimentally has been determined. The larger this anisotropy is, the better a molecule is suited as a molecular nanomagnet. Such nanomagnets have a wide range of potential applications, for example, in energy-efficient data storage. Researchers from the Max Planck Institute for Kohlenforschung (MPI KOFO), the Joint Lab EPR4Energy of the Max Planck Institute for Chemical Energy Conversion (MPI CEC) and the Helmholtz-Zentrum Berlin were involved in the study.
The research involved a bismuth complex synthesized in the group of Josep Cornella (MPI KOFO). This molecule has unique magnetic properties that a team led by Frank Neese (MPI KOFO) recently predicted in theoretical studies. So far, however, all attempts to measure the magnetic properties of the bismuth complex and thus experimentally confirm the theoretical predictions have failed.
This important step has now been achieved by using THz electron paramagnetic resonance spectroscopy (THz-EPR) at the synchrotron radiation source BESSY II, which is operated by the HZB in Berlin.
“The results show in a fascinating way that our method can be used to determine extremely high values of the magnetic anisotropy with high accuracy. Through our cooperation with scientists from fundamental research, we are thereby making a great step forward in the understanding of this class of materials,” says Tarek Al Said (HZB), first author of the study, which was recently published in the renowned Journal of the American Chemical Society.
- Porous Radical Organic framework improves lithium-sulphur batteriesA team led by Prof. Yan Lu, HZB, and Prof. Arne Thomas, Technical University of Berlin, has developed a material that enhances the capacity and stability of lithium-sulphur batteries. The material is based on polymers that form a framework with open pores (known as radical-cationic covalent organic frameworks or COFs). Catalytically accelerated reactions take place in these pores, firmly trapping polysulphides, which would shorten the battery life. Some of the experimental analyses were conducted at the BAMline at BESSY II.
- Metallic nanocatalysts: what really happens during catalysisUsing a combination of spectromicroscopy at BESSY II and microscopic analyses at DESY's NanoLab, a team has gained new insights into the chemical behaviour of nanocatalysts during catalysis. The nanoparticles consisted of a platinum core with a rhodium shell. This configuration allows a better understanding of structural changes in, for example, rhodium-platinum catalysts for emission control. The results show that under typical catalytic conditions, some of the rhodium in the shell can diffuse into the interior of the nanoparticles. However, most of it remains on the surface and oxidises. This process is strongly dependent on the surface orientation of the nanoparticle facets.
- KlarText Prize for Hanna TrzesniowskiThe chemist has been awarded the prestigious KlarText Prize for Science Communication by the Klaus Tschira Foundation.