Focused lecture hosted by HYP*MOL & RTG 2721 with Mario Chiesa

HYP*MOL together with RTG 2721 ^1,2,3H will welcome you to a focused lecture on Monday, 26.05.2025 at 15:00. Invited speaker is Mario Chiesa, who will talk about EPR Spectroscopy at the Solid-Gas Interface. The event will take place in the small lecture hall of the chemistry faculty. We look forward to welcoming you.

Radicals—chemical species containing one or more unpaired electrons—typically engage in reactions through electron pairing or transfer mechanisms. At solid surfaces, radicals can be stabilized through specific interactions, while also exhibiting distinct reactivity toward incoming adsorbates. The significance of surface radicals stems from their central role in a wide range of surface phenomena relevant to fields such as heterogeneous catalysis, photochemistry, electrochemistry, corrosion science, microelectronics, optoelectronics, and, more broadly, nanoscience and nanotechnology. Nanostructured or mesostructured solids bridge the gap between atomic and macroscopic matter. These materials often exhibit unique chemical and physical properties due to size-dependent and interfacial effects. Such effects can enhance reactivity and promote the formation of unusual radical species, particularly in structured solids featuring micro- and mesopores. As Wolfgang Pauli famously stated, “God created the solids, the devil their surfaces,” capturing the inherent challenges in surface characterization—ranging from complex sample preparation and low symmetry to limited experimental sensitivity. While numerous techniques exist to study adsorbates, far fewer can probe the interaction and structure of the adsorbate surface system at a molecular level. In this talk, I will demonstrate the capabilities of Electron Paramagnetic Resonance (EPR) spectroscopy in addressing this challenge—provided the adsorbate–surface system is paramagnetic. EPR offers unique insights into the nature of radicals at the solid-gas interface and serves as a powerful tool for characterizing their structure and dynamics.