Humboldt Research Fellowship Luming Yang

Development and application of liquid-state Overhauser dynamic nuclear polarization at high magnetic field (≥ 9.4 Tesla)

Liquid-state nuclear magnetic resonance (NMR) spectroscopic methods are crucial in the structural elucidation of organic molecules and chemical reactions monitoring. The sensitivity of NMR for heteronucleus such as 13C, however, is often limited by the low gyromagnetic ratio and natural abundance of the NMR-active isotope. One emergent approach to improve the sensitivity of liquid-state NMR at high magnetic-field (≥ 9.4 T) is through Overhauser dynamic nuclear polarization (ODNP), whereby the polarization of a radical-centered electron spin is transferred to 13C nuclei of the target molecule under microwave irradiation. In this project, we focus on the development and application of ODNP in the enhancement of liquid-state NMR performance for 13C and other nuclei at 9.4 T. Specifically, we investigate the viability and efficiency of established NMR methods, including common polarization and coherence transfer mechanisms, upon application of ODNP. We also target at furthering the theoretical understanding of the ODNP mechanism and improving the ODNP efficiency through optimization of the sample preparation protocol. We envision this project could deliver new opportunities to the application of NMR in studying liquid systems in the context of chemical, biological, and material sciences.