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Radical-induced hetero-nuclear mixing and low-field $^{13}$C relaxation in solid pyruvic acid

Kouřilová, Hana 1; Jurkutat, Michael 1; Peat, David; Kouřil, Karel 1; Khan, Alixander S.; Horsewill, Anthony J.; MacDonald, James F.; Owers-Bradley, John; Meier, Benno ORCID iD icon 1,2
1 Institut für Biologische Grenzflächen (IBG), Karlsruher Institut für Technologie (KIT)
2 Institut für Physikalische Chemie (IPC), Karlsruher Institut für Technologie (KIT)

Abstract:

Radicals serve as a source of polarization in dynamic nuclear polarization, but may also act as polarization sink, in particular at low field. Additionally, if the couplings between the electron spins and different nuclear reservoirs are stronger than any of the reservoirs’ couplings to the lattice, radicals can mediate hetero-nuclear polarization transfer. Here, we report radical-enhanced $^{13}$C relaxation in pyruvic acid doped with trityl. Up to 40 K, we find a linear carbon $T_{1}$ field dependence between 5 mT and 2 T. We model the dependence quantitatively, and find that the presence of trityl accelerates direct hetero-nuclear polarization transfer at low fields, while at higher fields $^{13}$C relaxation is diffusion limited. Measurements of hetero-nuclear polarization transfer up to 600 mT confirm the predicted radical-mediated proton–carbon mixing.


Verlagsausgabe §
DOI: 10.5445/IR/1000153610
Veröffentlicht am 04.01.2023
Originalveröffentlichung
DOI: 10.1039/D2CP04535D
Scopus
Zitationen: 4
Web of Science
Zitationen: 3
Dimensions
Zitationen: 7
Cover der Publikation
Zugehörige Institution(en) am KIT Institut für Biologische Grenzflächen (IBG)
Institut für Physikalische Chemie (IPC)
Publikationstyp Zeitschriftenaufsatz
Publikationsdatum 30.11.2022
Sprache Englisch
Identifikator ISSN: 1463-9076, 1463-9084
KITopen-ID: 1000153610
HGF-Programm 43.35.01 (POF IV, LK 01) Platform for Correlative, In Situ & Operando Charakterizat.
Erschienen in Physical Chemistry Chemical Physics
Verlag Royal Society of Chemistry (RSC)
Band 24
Heft 46
Seiten 28242–28249
Projektinformation SFB 1527; HyPERiON (DFG, DFG KOORD, SFB 1527_1)
Nachgewiesen in Dimensions
Web of Science
Scopus
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