Dissolution dynamic nuclear polarization of deuterated molecules enhanced by cross-polarization

The authors want to thank Dr. Jean-Nicolas Dumez for helpful discussions; Sven Sieber, Michael Schenkel, Rolf Hensel, Jacco van Beek, Ion Prisucaru, and Armin Purea for contributions to the system design and implementation; and Frank Engelke, Pietro Lendi, Klemens Kessler, Daniel Eckert, Daniel Guy Baumann, Dirk Wilhelm, Roberto Seydoux, Uwe Wagner, Cengiz Cetrefli, Tonio Gianotti, and Jorg Hinderer for contributions to the system specification. Some of the work in this article employed the SpinDynamica code for Mathematica, programmed by Malcolm H. Levitt, with contributions from Jyrki Rantaharju, Andreas Brinkmann, and Soumya Singha Roy, available at www.SpinDynamica.soton.ac.uk.International audienceWe present novel means to hyperpolarize deuterium nuclei in 13CD2 groups at cryogenic temperatures. The method is based on cross-polarization from 1H to 13C and does not require any radio-frequency fields applied to the deuterium nuclei. After rapid dissolution, a new class of long-lived spin states can be detected indirectly by 13C NMR in solution. These long-lived states result from a sextet-triplet imbalance (STI) that involves the two equivalent deuterons with spin I = 1. An STI has similar properties as a triplet-singlet imbalance that can occur in systems with two equivalent I = 12/ spins. Although the lifetimes T STI are shorter than T 1(Cz), they can exceed the life-time T 1(Dz) of deuterium Zeeman magnetization by a factor of more than 20