Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.
Phys Chem Chem Phys. 2010 Jun 14;12(22):5902-10. doi: 10.1039/c002304n. Epub 2010 May 10.
Water (1)H relaxation rate measurements of (15)N-(2)H-TEMPONE solutions at temperatures ranging from 298 to 328 K have been performed as a function of magnetic field from 0.00023 to 9.4 T, corresponding to (1)H Larmor frequencies of 0.01 to 400 MHz. The relaxation profiles were analyzed according to the full theory for dipolar and contact relaxation, and used to estimate the coupling factor responsible for observed solution DNP effects. The experimental DNP enhancement at (1)H Larmor frequency of 15 MHz obtained by saturating one of the lines of the (15)N doublet is only ca. 20% lower than the limiting value predicted from the relaxation data, indicating that the experimental DNP setup is nearly optimal, the residual discrepancy arising from incomplete saturation of the other line.
对 298 至 328 K 温度范围内的（15）N-（2）H-TEMPONE 溶液的（1）H 弛豫率进行了测量，磁场范围从 0.00023 至 9.4 T，对应（1）H 拉莫尔频率从 0.01 至 400 MHz。根据偶极子和接触弛豫的全理论对弛豫曲线进行了分析，并用于估计观察到的溶液 DNP 效应的耦合因子。通过饱和（15）N 二重峰的一条线在 15 MHz 的（1）H 拉莫尔频率下获得的实验 DNP 增强仅比从弛豫数据预测的极限值低约 20%，这表明实验 DNP 装置几乎是最佳的，剩余的差异来自于另一条线未完全饱和。
