title: High-field dynamic nuclear polarization with high-spin transition metal ions.
abstract: We report the dynamic nuclear polarization of (1)H spins in magic-angle-spinning spectra recorded at 5 T and 84 K via the solid effect using Mn(2+) and Gd(3+) complexes as polarizing agents. We show that the magnitude of the enhancements can be directly related to the effective line width of the central (m(S) = -1/2 → +1/2) EPR transition. Using a Gd(3+) complex with a narrow central transition EPR line width of 29 MHz, we observed a maximum enhancement of ∼13, which is comparable to previous results on the narrow-line-width trityl radical.
authors: Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States.
authors: Björn
authors: B
authors: Corzilius
authors: Albert A
authors: AA
authors: Smith
authors: Alexander B
authors: AB
authors: Barnes
authors: Claudio
authors: C
authors: Luchinat
authors: Ivano
authors: I
authors: Bertini
authors: Robert G
authors: RG
authors: Griffin
mesh_terms: D002614:Chelating Agents / Q000737:chemistry; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D005682:Gadolinium / Q000737:chemistry*; D007477:Ions / Q000737:chemistry; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008345:Manganese / Q000737:chemistry*
chemical_list: D002614:Chelating Agents; D007477:Ions; D008024:Ligands; D008345:Manganese; D005682:Gadolinium