TY - JOUR

T1 - Complete magnetic field dependence of SABRE-derived polarization

AU - Kiryutin, Alexey S.

AU - Yurkovskaya, Alexandra V.

AU - Zimmermann, Herbert

AU - Vieth, Hans Martin

AU - Ivanov, Konstantin L.

N1 - Copyright © 2017 John Wiley & Sons, Ltd.

PY - 2018/7/1

Y1 - 2018/7/1

N2 - Signal amplification by reversible exchange (SABRE) is a promising hyperpolarization technique, which makes use of spin-order transfer from parahydrogen (the H2 molecule in its singlet spin state) to a to-be-polarized substrate in a transient organometallic complex, termed the SABRE complex. In this work, we present an experimental method for measuring the magnetic field dependence of the SABRE effect over an ultrawide field range, namely, from 10 nT to 10 T. This approach gives a way to determine the complete magnetic field dependence of SABRE-derived polarization. Here, we focus on SABRE polarization of spin-1/2 hetero-nuclei, such as 13C and 15N and measure their polarization in the entire accessible field range; experimental studies are supported by calculations of polarization. Features of the field dependence of polarization can be attributed to level anticrossings in the spin system of the SABRE complex. Features at magnetic fields of the order of 100 nT-1 μT correspond to "strong coupling" of protons and hetero-nuclei, whereas features found in the mT field range stem from "strong coupling" of the proton system. Our approach gives a way to measuring and analyzing the complete SABRE field dependence, to probing NMR parameters of SABRE complexes and to optimizing the polarization value.

AB - Signal amplification by reversible exchange (SABRE) is a promising hyperpolarization technique, which makes use of spin-order transfer from parahydrogen (the H2 molecule in its singlet spin state) to a to-be-polarized substrate in a transient organometallic complex, termed the SABRE complex. In this work, we present an experimental method for measuring the magnetic field dependence of the SABRE effect over an ultrawide field range, namely, from 10 nT to 10 T. This approach gives a way to determine the complete magnetic field dependence of SABRE-derived polarization. Here, we focus on SABRE polarization of spin-1/2 hetero-nuclei, such as 13C and 15N and measure their polarization in the entire accessible field range; experimental studies are supported by calculations of polarization. Features of the field dependence of polarization can be attributed to level anticrossings in the spin system of the SABRE complex. Features at magnetic fields of the order of 100 nT-1 μT correspond to "strong coupling" of protons and hetero-nuclei, whereas features found in the mT field range stem from "strong coupling" of the proton system. Our approach gives a way to measuring and analyzing the complete SABRE field dependence, to probing NMR parameters of SABRE complexes and to optimizing the polarization value.

KW - N-15 HYPERPOLARIZATION

KW - REVERSIBLE EXCHANGE

KW - PARA-HYDROGEN

KW - SPIN HYPERPOLARIZATION

KW - NMR

KW - PARAHYDROGEN

UR - http://www.scopus.com/inward/record.url?scp=85039852285&partnerID=8YFLogxK

U2 - 10.1002/mrc.4694

DO - 10.1002/mrc.4694

M3 - Article

C2 - 29230864

AN - SCOPUS:85039852285

VL - 56

SP - 651

EP - 662

JO - Magnetic Resonance in Chemistry

JF - Magnetic Resonance in Chemistry

SN - 0749-1581

IS - 7

ER -