Solid-state nuclear magnetic resonance under magic angle spinning (MAS) enhanced with dynamic nuclear polarization (DNP) is a powerful approach to characterize many important classes of materials, allowing access to previously inaccessible structural and dynamic parameters. Here, we present the first DNP MAS experiments using a 0.7 mm MAS probe, which allows us to reach spinning frequencies of 65 kHz, with microwave irradiation, at 100 K. At the highest magnetic field available for DNP today (21.1 T), we find that the polarizing agent HyTEK2 provides DNP enhancements as high as 200 at a spinning rate of 65 kHz at 100 K, and BDPA yields an enhancement of 106 under the same conditions. Fast spinning rates enable excellent DNP performance, but they also yield unprecedented ¹H resolution under DNP conditions. We report well-resolved ¹H-detected ¹H–¹³C and ¹H–¹⁵N correlation spectra of microcrystalline histidine·HCl·H₂O.

中文翻译：

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65 kHz魔角旋转使在21.15 T处200的动态核极化增强。

借助动态核极化（DNP）增强的魔角旋转（MAS）下的固态核磁共振是表征许多重要材料类别的强大方法，可以访问以前无法访问的结构和动态参数。在这里，我们展示了使用0.7 mm MAS探头进行的首个DNP MAS实验，这使我们能够在100 K的微波辐射下达到65 kHz的自旋频率。在当今DNP可用的最高磁场（21.1 T）下，我们发现偏振剂HyTEK2在100 K下以65 kHz的自旋速率可提供高达200的DNP增强，而BDPA在相同条件下可产生106的增强。快速纺丝速度可实现出色的DNP性能，但它们也可产生空前的¹在DNP条件下的H分辨率。我们报告良好分辨¹ H-检测¹ H- ¹³ C和¹ H- ¹⁵微晶组氨酸的N个相关光谱·HCl的·H ₂ O.