Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.
J Am Chem Soc. 2012 Mar 14;134(10):4537-40. doi: 10.1021/ja212054e. Epub 2012 Feb 28.
A new biradical polarizing agent, bTbtk-py, for dynamic nuclear polarization (DNP) experiments in aqueous media is reported. The synthesis is discussed in light of the requirements of the optimum, theoretical, biradical system. To date, the DNP NMR signal enhancement resulting from bTbtk-py is the largest of any biradical in the ideal glycerol/water solvent matrix, ε = 230. EPR and X-ray crystallography are used to characterize the molecule and suggest approaches for further optimizing the biradical distance and relative orientation.
本文报道了一种新型双自由基极化剂 bTbtk-py，可用于水相中的动态核极化 (DNP) 实验。根据最佳理论双自由基体系的要求讨论了其合成。迄今为止，bTbtk-py 产生的 DNP NMR 信号增强是理想甘油/水溶剂基质中任何双自由基中最大的，ε = 230。使用 EPR 和 X 射线晶体学对分子进行了表征，并提出了进一步优化双自由基距离和相对取向的方法。
