Over 35% liquid-state 13C polarization via dissolution dynamic nuclear polarization at 7 T and 1 K with ubiquitous nitroxyl radicals

The most versatile method to increase liquid-state 13C NMR sensitivity is dissolution dynamic nuclear polarization. The use of trityl radicals is usually required to obtain very large 13C polarization via this technique. We herein demonstrate that up to 35% liquid-state 13C polarization can be obtained in about 1.5 h with ubiquitous nitroxyl radicals in 13C-labeled sodium salts by partially deuterating the solvents and using a polarizer operating at 1 K and 7 T.