Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States.
J Am Chem Soc. 2011 Apr 20;133(15):5648-51. doi: 10.1021/ja1109002. Epub 2011 Mar 29.
We report the dynamic nuclear polarization of (1)H spins in magic-angle-spinning spectra recorded at 5 T and 84 K via the solid effect using Mn(2+) and Gd(3+) complexes as polarizing agents. We show that the magnitude of the enhancements can be directly related to the effective line width of the central (m(S) = -1/2 → +1/2) EPR transition. Using a Gd(3+) complex with a narrow central transition EPR line width of 29 MHz, we observed a maximum enhancement of ∼13, which is comparable to previous results on the narrow-line-width trityl radical.
我们报告了在 5 T 和 84 K 下通过固态效应使用 Mn(2+)和 Gd(3+) 配合物作为极化剂在魔角旋转光谱中记录的（1）H 自旋的动态核极化。我们表明，增强的幅度可以直接与中央（m(S) = -1/2 → +1/2）EPR 跃迁的有效线宽相关。使用具有 29 MHz 窄中心跃迁 EPR 线宽的 Gd(3+)配合物，我们观察到最大增强约为 13，这与以前关于窄线宽三苯甲基自由基的结果相当。
