Water-soluble narrow-line radicals for dynamic nuclear polarization.
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.
Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA.
Olesya
O
Haze
Björn
B
Corzilius
Albert A
AA
Smith
Robert G
RG
Griffin
Timothy M
TM
Swager
D000498:Allyl Compounds / Q000737:chemistry*; D004578:Electron Spin Resonance Spectroscopy; D005609:Free Radicals / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D012995:Solubility; D014867:Water / Q000737:chemistry*
D000498:Allyl Compounds; D005609:Free Radicals; C416323:bis-diphenylene-phenyl-allyl; D014867:Water