Liquid-state dynamic nuclear polarization using triarylmethyl radicals as a polarizing agent in high magnetic fields

• Applicant: Dr. Andrei Kuzhelev
• Subject Area: Physical Chemistry of Molecules, Liquids and Interfaces, Biophysical Chemistry
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 518679424

The goal of the project is to obtain a deeper insight into solid-effect DNP in viscous liquids at room temperatures and high magnetic fields. For this purpose, we will perform solid-effect DNP experiments in viscous media doped with a triarylmethyl radical showing high stability and very low hyperfine and g-anisotropies. The efficiency of the polarization transfer from the unpaired electron spin to 1H as well as 13C spins of a viscous solution will be investigated for triarylmethyl radicals of different structures, different surroundings (glycerol, lipid bilayers, or ionic liquids), and as a function of the viscosity. In parallel, we will perform CW and pulsed EPR measurements at low magnetic fields (10 GHz/0.33 T and 34 GHz/1.2 T) to quantitatively determine the rotational correlation time as well as an electron–nuclear hyperfine interaction of the polarizing agents in the proposed solutions. We believe that the experimental obtained DNP and EPR data will allow us to draw detailed conclusions about the mechanism and polarization transfer pathway responsible for solid-effect DNP in viscous media.

• DFG Programme: Research Grants
• International Connection: Netherlands
• Co-Investigators: Professor Dr. Clemens Glaubitz; Professor Dr. Thomas F. Prisner; Professor Dr. Olav Schiemann
• Cooperation Partner: Dr. Svetlana Pylaeva