Protonation tuned dipolar order mediated <SUP>1</SUP>H→<SUP>13</SUP>C cross-polarization for dissolution-dynamic nuclear polarization experiments
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Accepted version
Author(s)
Elliott, Stuart J
Stern, Quentin
Cala, Olivier
Jannin, Sami
Type
Journal Article
Abstract
A strategy of dipolar order mediated nuclear spin polarization transfer has recently been combined with dissolution-dynamic nuclear polarization (dDNP) and improved by employing optimized shaped radiofrequency pulses and suitable molecular modifications. In the context of dDNP experiments, this offers a promising means of transferring polarization from high-gamma 1H spins to insensitive 13C spins with lower peak power and lower energy compared with state-of-the-art cross-polarization schemes. The role of local molecular groups and the glassing matrix protonation level are both postulated to play a key role in the polarization transfer pathway via an intermediary reservoir of dipolar spin order. To gain appreciation of the mechanisms involved in the dipolar order mediated polarization transfer under dDNP conditions, we investigate herein the influence of the pivotal characteristics of the sample makeup: (i) revising the protonation level for the constituents of the DNP glass; and (ii) utilizing deuterated molecular derivatives. Experimental demonstrations are presented for the case of [1–13C]sodium acetate. We find that the proton sample molarity has a large impact on both the optimal parameters and the performance of the dipolar order mediated cross-polarization sequence, with the 13C signal build-up time drastically shortened in the case of high solvent protonation levels. In the case of a deuterated molecular derivative, we observe that the nearby 2H substituted methyl group is deleterious to the 1H→13C transfer phenomenon (particularly at low levels of sample protonation). Overall, increased solvent protonation makes the dipolar order governed polarization transfer significantly faster and more efficient. This study sheds light on the influential sample formulation traits which govern the dipolar order-controlled transfer of polarization and indicates that the polarization transfer efficiencies of deuterated molecules can be boosted and reach high performances simply by adequate solvent protonation.
Date Issued
2021-12-01
Date Acceptance
2021-10-13
Citation
Solid State Nuclear Magnetic Resonance, 2021, 116
ISSN
0926-2040
Publisher
Elsevier
Journal / Book Title
Solid State Nuclear Magnetic Resonance
Volume
116
Copyright Statement
© 2021 Published by Elsevier Inc. This manuscript version is made available under the CC-BY-NC-ND 4.0 license https://creativecommons.org/licenses/by-nc-nd/4.0/
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/34823210
PII: S0926-2040(21)00050-3
Subjects
Chemistry
Chemistry, Physical
CP
dCP
dDNP
Dipolar order
DNP
Hyperpolarization
HYPERPOLARIZATION
MAGNETIC-RESONANCE
METABOLITES
NMR
Physical Sciences
Physics
Physics, Atomic, Molecular & Chemical
Physics, Condensed Matter
Protonation
Science & Technology
SIGNAL
SOLIDS
Spectroscopy
SPECTROSCOPY
Technology
TEMPERATURES
WATER
ZEEMAN
Publication Status
Published
Coverage Spatial
Netherlands
Article Number
ARTN 101762
Date Publish Online
2021-10-16