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Continuous Re‐hyperpolarization of Nuclear Spins Using Parahydrogen: Theory and Experiment
Author(s) -
Hövener JanBernd,
Knecht Stephan,
Schwaderlapp Niels,
Hennig Jürgen,
von Elverfeldt Dominik
Publication year - 2014
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.201402177
Subject(s) - hyperpolarization (physics) , spin isomers of hydrogen , spins , polarization (electrochemistry) , magnetic field , induced polarization , chemistry , singlet state , chemical physics , nuclear magnetic resonance , molecular physics , condensed matter physics , physics , atomic physics , nuclear magnetic resonance spectroscopy , quantum mechanics , organic chemistry , electrical resistivity and conductivity , excited state , hydrogen
The continuous re‐hyperpolarization of nuclear spins in the liquid state by means of parahydrogen ( para ‐H 2 ) and chemical exchange at low magnetic fields was recently discovered and offers intriguing perspectives for many varieties of magnetic resonance. In this contribution, we provide a theoretical assessment of this effect and compare the results to experimental data. A distinct distribution of polarization is found, which shares some features with experimental data and, interestingly, does not directly correspond to the loss of the singlet order of para ‐H 2 . We derived expressions for the magnetic field and para ‐H 2 –substrate interaction time, for which the polarization transfer is maximal. This work sheds light onto the effect of continuous hyperpolarization and elucidates the underlying mechanism, which may facilitate the development of an optimized catalyst. As an application, continuous hyperpolarization may enable highly sensitive nuclear magnetic resonance at very low magnetic fields, for example, for the cost‐efficient screening of drugs.