Dynamic nuclear polarization experiments at 14.1 T for solid-state NMR

作者：Matsuki Yoh; Takahashi Hiroki; Ueda Keisuke; Idehara Toshitaka; Ogawa Isamu; Toda Mitsuru; Akutsu Hideo; Fujiwara Toshimichi^*

来源：Physical Chemistry Chemical Physics, 2010, 12(22): 5799-5803.

DOI：10.1039/c002268c

Instrumentation for high-field dynamic nuclear polarization (DNP) at 14.1 T was developed to enhance the nuclear polarization for NMR of solids. The gyrotron generated 394.5 GHz submillimeter (sub-mm) wave with a power of 40 W in the second harmonic TE(0,6) mode. The sub-mm wave with a power of 0.5- 3 W was transmitted to the sample in a low-temperature DNP-NMR probe with a smooth-wall circular waveguide system. The (1)H polarization enhancement factor of up to about 10 was observed for a (13)C-labeled compound with nitroxyl biradical TOTAPOL. The DNP enhancement was confirmed by the static magnetic field dependence of the NMR signal amplitude at 90 K. Improvements of the high-field DNP experiments are discussed.

• 出版日期2010