Cross Polarization for Dissolution Dynamic Nuclear Polarization Experiments at Readily Accessible

Cross polarization can provide significant enhancements with respect to direct polarization of low-c nuclei such as C. Substantial gains in sample throughput (shorter polarization times) can be achieved by exploiting shorter buildup times sDNP( H) \ sDNP( C). To polarize protons rather than low-c nuclei, nitroxide radicals with broad ESR resonances such as TEMPO are more appropriate than Trityl and similar carbon-based radicals that have narrow lines. With TEMPO as polarizing agent, the main Dynamic Nuclear Polarization (DNP) mechanism is thermal mixing (TM). Cross polarization makes it possible to attain higher polarization levels at 2.2 K than one can obtain with direct DNP of low-c nuclei with TEMPO at 1.2 K, thus avoiding complex cryogenic technology. A. Bornet S. Jannin (&) G. Bodenhausen Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), Batochime, 1015 Lausanne, Switzerland e-mail: [email protected] R. Melzi Bruker Italia S.r.l, Viale V. Lancetti, 43, 20158 Milan, Italy G. Bodenhausen Département de Chimie, Ecole Normale Supérieure, 24 Rue Lhomond, 75231 Paris Cedex 05, France G. Bodenhausen Université Pierre-et-Marie Curie, Paris, France G. Bodenhausen UMR 7203, CNRS/UPMC/ENS, Paris, France 123 Appl Magn Reson (2012) 43:107–117 DOI 10.1007/s00723-012-0358-1 Applied