Journal Article

FZJ-2020-00642

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Heteronuclear cross-relaxation effect modulated by the dynamics of N-functional groups in the solid state under 15N DP-MAS DNP

Park, H. (Corresponding author)FZJ*RWTH* ; Uluca-Yazgi, B.FZJ* ; Heumann, S. ; Schlögl, R. ; Granwehr, J.FZJ*RWTH* ; Heise, H.FZJ* ; Schleker, P. P. M.FZJ*

2020
Elsevier Amsterdam [u.a.]

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Please use a persistent id in citations: http://hdl.handle.net/2128/24325  doi:10.1016/j.jmr.2020.106688

Abstract: In a typical magic-angle spinning (MAS) dynamic nuclear polarization (DNP) nuclear magnetic resonance (NMR) experiment, several mechanisms are simultaneously involved when transferring much larger polarization of electron spins to NMR active nuclei of interest. Recently, specific cross-relaxation enhancement by active motions under DNP (SCREAM-DNP) [Daube et al. JACS 2016] has been reported as one of these mechanisms. Thereby 13C enhancement with inverted sign was observed in a direct polarization (DP) MAS DNP experiment, caused by reorientation dynamics of methyl that was not frozen out at 100 K. Here, we report on the spontaneous polarization transfer from hyperpolarized 1H to both primary amine and ammonium nitrogens, resulting in an additional positive signal enhancement in the 15N NMR spectra during 15N DP-MAS DNP. The cross-relaxation induced signal enhancement (CRE) for 15N is of opposite sign compared to that observed for 13C due to the negative sign of the gyromagnetic ratio of 15N. The influence on CRE efficiency caused by variation of the radical solution composition and by temperature was also investigated.

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Contributing Institute(s):

1. Grundlagen der Elektrochemie (IEK-9)
2. Strukturbiochemie (ICS-6)

Research Program(s):

1. 131 - Electrochemical Storage (POF3-131) (POF3-131)
2. HITEC - Helmholtz Interdisciplinary Doctoral Training in Energy and Climate Research (HITEC) (HITEC-20170406) (HITEC-20170406)

Appears in the scientific report 2020

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Database coverage:
; ; ; Clarivate Analytics Master Journal List ; Current Contents - Life Sciences ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; IF < 5 ; JCR ; NCBI Molecular Biology Database ; Nationallizenz ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Web of Science Core Collection

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