Water-soluble narrow-line radicals for dynamic nuclear polarization.

TitleWater-soluble narrow-line radicals for dynamic nuclear polarization.
Publication TypeJournal Article
Year of Publication2012
AuthorsHaze, O, Corzilius, B\örn, Smith, AA, Griffin, RG, Swager, TM
JournalJournal of the American Chemical Society
Date Publishedsep
KeywordsAllyl Compounds, Allyl Compounds: chemistry, Electron Spin Resonance Spectroscopy, Free Radicals, Free Radicals: chemistry, Magnetic Resonance Spectroscopy, Solubility, Water, Water: chemistry

The synthesis of air-stable, highly water-soluble organic radicals containing a 1,3-bis(diphenylene)-2-phenylallyl (BDPA) core is reported. A sulfonated derivative, SA-BDPA, retains the narrow electron paramagnetic resonance linewidth (<30 MHz at 5 T) of the parent BDPA in highly concentrated glycerol/water solutions (40 mM), which enables its use as polarizing agent for solid effect dynamic nuclear polarization (SE DNP). A sensitivity enhancement of 110 was obtained in high-field magic-angle-spinning (MAS) NMR experiments. The ease of synthesis and high maximum enhancements obtained with the BDPA-based radicals constitute a major advance over the trityl-type narrow-line polarization agents.