Dynamic Polarization of 7Li Nuclei in Solution

Lithium dynamic nuclear polarization (DNP) parameters, obtained at 74 G, are reported for lithium salts in solvents containing OH groups. Observed ⁷Li NMR enhancements indicate that the most sensitive experimental variable governing the degree of scalar coupling is the choice of free radical. Of the five radicals used, only nitroxide radicals lead to appreciable scalar coupling. Lithium $T_1$ measurements suggest clustering in the solutions with different radicals avoiding lithium‐containing regions to different degrees. Only nitroxide radicals appear to compete effectively with ROH to solvate lithium.