Research Institute for Material and Chemical Measurement, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki, 305-8565, Japan.
Research Institute for Material and Chemical Measurement, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki, 305-8565, Japan.
Solid State Nucl Magn Reson. 2017 Oct;87:24-28. doi: 10.1016/j.ssnmr.2017.07.002. Epub 2017 Jul 8.
Mechanisms of the H spin-lattice relaxation in NHHPO were studied in detail by use of the effect of magic angle spinning on the relaxation. The acid and the ammonium protons have different relaxation times at the spinning rates higher than 10 kHz due to suppression of spin diffusion between the two kinds of protons. The intrinsic relaxation times not affected by the spin diffusion and the spin-diffusion assisted relaxation times were evaluated separately, taking into consideration temperature dependence. Both mechanisms contribute to the H relaxation of the acid protons comparatively. The spin-diffusion assisted relaxation mechanism was suppressed to the level lower than the experimental errors at the spinning rate of 30 kHz.
通过利用魔角旋转对弛豫的影响，详细研究了 NHHPO 中 H 的自旋晶格弛豫机制。由于两种质子之间的自旋扩散被抑制，在高于 10 kHz 的旋转速度下，酸质子和铵质子具有不同的弛豫时间。分别评估了不受自旋扩散影响的固有弛豫时间和自旋扩散辅助弛豫时间，同时考虑了温度依赖性。这两种机制都对酸质子的 H 弛豫有贡献。在 30 kHz 的旋转速度下，自旋扩散辅助弛豫机制被抑制到低于实验误差的水平。
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