Fabian Hecker

Residue‐Specific Signatures of Structural Water Identified by Dissolution Dynamic Nuclear Polarization with UV‐Generated Radicals Structural water molecules in proteins are notoriously hard to detect in solution. Hyperpolarized water with UV radicals as polarizing agents provides the sensitivity and resolution to detect residue...

Residue‐Specific Signatures of Structural Water Identified by Dissolution Dynamic Nuclear Polarization with UV‐Generated Radicals - Hecker - Angewandte Chemie International Edition - Wiley Online Library onlinelibrary.wiley.com/doi/10.1002/...

Uncovering a Multispecies Radical Network in UV-Irradiated Pyruvic Acid α-Keto acids readily form radicals upon UV irradiation, shaping their use as radical precursors in dissolution dynamic nuclear polarization (dDNP) and governing their role in atmospheric chemistry. Their rich photochemistry, however, is not captured by current electron paramagnetic resonance (EPR) experimental evidence, and assignment to a single ketyl species is a simplification obscuring their broader radical behavior. To probe this, we combined isotope labeling with 9.5 GHz EPR spectroscopy to monitor irradiation-time-resolved buildup and temperature-dependent decay of UV-generated radicals. High-frequency EPR (94 GHz) and DFT-guided simulations aided spectral deconvolution, revealing at least four distinct radical species originating from pyruvic acid. We identified the dominant monomeric ketyl radical, a methyl radical, a carboxylate radical anion, and a dimeric ketyl species. Thus, α-keto acids exhibit multispecies radical chemistry under UV-irradiation, which should be considered when interpreting solid-state ESR or DNP behavior and atmospheric processes.

Uncovering a Multispecies Radical Network in UV-Irradiated Pyruvic Acid | The Journal of Physical Chemistry Letters pubs.acs.org/doi/10.1021/...

Congratulations to Dr Annemarie Kehl on winning the 12th Bruker #ESR Thesis Prize!
She'll present her work in a prize lecture at the 59th International Meeting of the @esr-group.bsky.social Spectroscopy Group on April 13–16 in Colchester, UK.
Learn more: goto.bruker.com/4pOlgb4

@rsc.org #RSCESR2026

2025 IES John Weil Young Investigator Award: Nino Wili his outstanding contributions to theory and instrumentation in the field of EPR spectroscopy.