DNP Surface Enhanced Solid-State NMR Spectroscopy: Recent Developments and Applications

While the fundamental principles of Dynamic Nuclear Polarization (DNP) and the first proofs of concept were demonstrated 70 years ago, it is only recently that this method became a game-changing technology to overcome the sensitivity barrier of solid-state Nuclear Magnetic Resonance (NMR) spectroscopy under Magic Angle Spinning (MAS). For the last twenty years, ongoing advances, notably in the instrumentation, have democratized this approach, with renewed application breakthroughs.
DNP enhanced solid-state NMR has notably developed as a powerful approach for an in-depth structural characterization of functionalized surfaces and materials. In this presentation, we will first describe unique DNP NMR methodologies to disclose, with atomic resolution, individual surface structures in complex multi-site environments, a long-standing challenge in the field of heterogeneous catalysts (2-3).
The efficiency of the continuous-wave DNP critically depends on the structure and properties of the polarizing agents (PA) hosting the free electrons (4). In this presentation we will also review our recent effort at designing PA with improved efficiency, especially at high magnetic field and very fast MAS frequencies.

(1) Berruyer et al, A. eMagRes 2018, 7, 93–104.
(2) Jabbour et al, J. Am. Chem. Soc. 2022, 144, 10270–10281.
(3) Wang et al, J. Am. Chem. Soc. 2022, 144, 21530–21543.
(4) Menzildjian et al, Chem. Sci. 2023, 14, 6120–6148.