|Title||Water-soluble narrow-line radicals for dynamic nuclear polarization.|
|Publication Type||Journal Article|
|Year of Publication||2012|
|Authors||Haze, O, Corzilius, B\örn, Smith, AA, Griffin, RG, Swager, TM|
|Journal||Journal of the American Chemical Society|
|Keywords||Allyl 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.