Sensitivity improvement in variable very high frequency EPR for applications in catalysis and protein research

• Applicant: Dr. Alexander Schnegg
• Subject Area: Analytical Chemistry
• Term: from 2012 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 221296626

High spin transition metal ions (TMIs) important in proteins and (photo) catalytic reactions will be characterized by novel variable very high frequency EPR methods. TMI complexes frequently exhibit paramagnetic metal cores with multiple unpaired electrons in high spin states. Due to instrumental constraints, investigation of high spin states exhibiting large zero field splittings (ZFS) have been limited until now. To lift this restriction, dedicated very high frequency (263 GHz) EPR and Frequency Domain Fourier Transform THz-EPR (FD-FT THz-EPR) methods with increased detection sensitivity and application range are further developed and applied. Novel FD-FT THz-EPR and 263 GHz EPR detection schemes will enable us to monitor the EPR of transient light induced TMI states and catalytic reaction intermediates from GHz to THz frequencies. Numerical EPR routines based on the public domain EPR simulation package EasySpin will be developed to simulate FD-EPR spectra. The intention is to apply FD-FT THz-EPR and 263 GHz EPR to provide information on function determining TMI cores in catalytic reactions and proteins to shed new light on their structure function relationship.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1601: New Frontiers in Sensitivity for EPR Spectroscopy: from Biological Cells to Nano Materials
• International Connection: USA
• Co-Investigator: Professor Dr. Robert Bittl
• Cooperation Partners: Professor Dr. Stefan Stoll; Professor Dr. Joshua A. Telser