English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Dynamic nuclear polarization (DNP) via the dissolution method has alleviated the insensitivity problem in liquid-state nuclear magnetic resonance (NMR) spectroscopy by amplifying the signals by several thousand-fold. This NMR signal amplification process emanates from the microwave-mediated transfer of high electron spin alignment to the nuclear spins at high magnetic field and cryogenic temperature. Since the interplay between the electrons and nuclei is crucial, the chemical composition of a DNP sample such as the type of free radical used, glassing solvents, or the nature of the target nuclei can significantly affect the NMR signal enhancement levels that can be attained with DNP. Herein, we have investigated the influence of 13 C isotopic labeling location on the DNP of a model 13 C compound, sodium acetate, at 3.35 T and 1.4 K using the narrow electron spin resonance (ESR) line width free radical trityl OX063. Our results show that the carboxyl 13 C spins yielded about twice the polarization produced in methyl 13 C spins. Deuteration of the methyl 13 C group, while proven beneficial in the liquid-state, did not produce an improvement in the 13 C polarization level at cryogenic conditions. In fact, a slight reduction of the solid-state 13 C polarization was observed when 2 H spins are present in the methyl group. Furthermore, our data reveal that there is a close correlation between the solid-state 13 C T 1 relaxation times of these samples and the relative 13 C polarization levels. The overall results suggest the achievable solid-state polarization of 13 C acetate is directly affected by the location of the 13 C isotopic labeling via the possible interplay of nuclear relaxation leakage factor and cross-talks between nuclear Zeeman reservoirs in DNP.

Influence of 13C Isotopic Labeling Location on Dynamic Nuclear Polarization of Acetate

Influence of ¹³C Isotopic Labeling Location on Dynamic Nuclear Polarization of Acetate