Next-Generation Radical Designs for Direct Polarization Transfer in High-Field DNP

Ribal Jabbour – @JabbourRibal

1H, 31P and 19F Direct Transfer in DNP-NMR. #GlobalnmrOC2024 @global_nmr pic.twitter.com/LZJ9AgXHl7

— Ribal Jabbour (@JabbourRibal) July 17, 2024

Traditional DNP transfer employs an indirect, spin-diffusion mediated process, transferring polarization from nuclei on the PA to solvent nuclei, and then to the target molecule nuclei. In contrast, direct transfer involves immediate polarization from the PA to the target molecule, bypassing any intermediary nuclei. We show the distinctions between indirect and direct transfer methods using AMUPol, a widely-used bis-nitroxide, at magnetic fields ranging from 9 T to 14 T. We demonstrate that with ASYMPol-POK (larger e-e couplings), superior direct transfer performance in deuterated DNP solvent is shown compared to AMUPol.