TY - JOUR
T1 - Gadolinium Effect at High-Magnetic-Field DNP: 70% 13C Polarization of [U-13C] Glucose Using Trityl
AU - Capozzi, Andrea
AU - Patel, Saket
AU - Wenckebach, W. Thomas
AU - Karlsson, Magnus
AU - Lerche, Mathilde H.
AU - Ardenkjær-Larsen, Jan Henrik
PY - 2019
Y1 - 2019
N2 - We show that the trityl electron spin resonance (ESR) features, crucial for an efficient dynamic nuclear polarization (DNP) process, are sample-composition-dependent. Working at 6.7 T and 1.1 K with a generally applicable DNP sample solvent mixture such as water/glycerol plus trityl, the addition of Gd3+ leads to a dramatic increase in [U-13C] glucose polarization from 37 ± 4% to 69 ± 3%. This is the highest value reported to date and is comparable to what can be achieved on pyruvic acid. Moreover, performing ESR measurements under actual DNP conditions, we provide experimental evidence that gadolinium doping not only shortens the trityl electron spin-lattice relaxation time but also modifies the radical g-tensor. The latter yielded a considerable narrowing of the ESR spectrum line width. Finally, in the frame of the spin temperature theory, we discuss how these two phenomena affect the DNP performance.
AB - We show that the trityl electron spin resonance (ESR) features, crucial for an efficient dynamic nuclear polarization (DNP) process, are sample-composition-dependent. Working at 6.7 T and 1.1 K with a generally applicable DNP sample solvent mixture such as water/glycerol plus trityl, the addition of Gd3+ leads to a dramatic increase in [U-13C] glucose polarization from 37 ± 4% to 69 ± 3%. This is the highest value reported to date and is comparable to what can be achieved on pyruvic acid. Moreover, performing ESR measurements under actual DNP conditions, we provide experimental evidence that gadolinium doping not only shortens the trityl electron spin-lattice relaxation time but also modifies the radical g-tensor. The latter yielded a considerable narrowing of the ESR spectrum line width. Finally, in the frame of the spin temperature theory, we discuss how these two phenomena affect the DNP performance.
U2 - 10.1021/acs.jpclett.9b01306
DO - 10.1021/acs.jpclett.9b01306
M3 - Journal article
C2 - 31181932
SN - 1948-7185
VL - 10
SP - 3420
EP - 3425
JO - Journal of Physical Chemistry Letters
JF - Journal of Physical Chemistry Letters
ER -