Research output: Contribution to journal › Article › peer-review
Quasi-resonance fluorine-19 signal amplification by reversible exchange. / Ariyasingha, Nuwandi M.; Lindale, Jacob R.; Eriksson, Shannon L. et al.
In: Journal of Physical Chemistry Letters, Vol. 10, No. 15, 01.08.2019, p. 4229-4236.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Quasi-resonance fluorine-19 signal amplification by reversible exchange
AU - Ariyasingha, Nuwandi M.
AU - Lindale, Jacob R.
AU - Eriksson, Shannon L.
AU - Clark, Grayson P.
AU - Theis, Thomas
AU - Shchepin, Roman V.
AU - Chukanov, Nikita V.
AU - Kovtunov, Kirill V.
AU - Koptyug, Igor V.
AU - Warren, Warren S.
AU - Chekmenev, Eduard Y.
PY - 2019/8/1
Y1 - 2019/8/1
N2 - We report on an extension of the quasi-resonance (QUASR) pulse sequence used for signal amplification by reversible exchange (SABRE), showing that we may target distantly J-coupled 19F-spins. Polarization transfer from the parahydrogen-derived hydrides to the 19F nucleus is accomplished via weak five-bond J-couplings using a shaped QUASR radio frequency pulse at a 0.05 T magnetic field. The net result is the direct generation of hyperpolarized 19F z-magnetization, derived from the parahydrogen singlet order. An accumulation of 19F polarization on the free ligand is achieved with subsequent repetition of this pulse sequence. The hyperpolarized 19F signal exhibits clear dependence on the pulse length, irradiation frequency, and delay time in a manner similar to that reported for 15N QUASR-SABRE. Moreover, the hyperpolarized 19F signals of 3-19F-14N-pyridine and 3-19F-15N-pyridine isotopologues are similar, suggesting that (i) polarization transfer via QUASR-SABRE is irrespective of the nitrogen isotopologue and (ii) the presence or absence of the spin-1/2 15N nucleus has no impact on the efficiency of QUASR-SABRE polarization transfer. Although optimization of polarization transfer efficiency to 19F (P 19F ≈ 0.1%) was not the goal of this study, we show that high-field SABRE can be efficient and broadly applicable for direct hyperpolarization of 19F spins.
AB - We report on an extension of the quasi-resonance (QUASR) pulse sequence used for signal amplification by reversible exchange (SABRE), showing that we may target distantly J-coupled 19F-spins. Polarization transfer from the parahydrogen-derived hydrides to the 19F nucleus is accomplished via weak five-bond J-couplings using a shaped QUASR radio frequency pulse at a 0.05 T magnetic field. The net result is the direct generation of hyperpolarized 19F z-magnetization, derived from the parahydrogen singlet order. An accumulation of 19F polarization on the free ligand is achieved with subsequent repetition of this pulse sequence. The hyperpolarized 19F signal exhibits clear dependence on the pulse length, irradiation frequency, and delay time in a manner similar to that reported for 15N QUASR-SABRE. Moreover, the hyperpolarized 19F signals of 3-19F-14N-pyridine and 3-19F-15N-pyridine isotopologues are similar, suggesting that (i) polarization transfer via QUASR-SABRE is irrespective of the nitrogen isotopologue and (ii) the presence or absence of the spin-1/2 15N nucleus has no impact on the efficiency of QUASR-SABRE polarization transfer. Although optimization of polarization transfer efficiency to 19F (P 19F ≈ 0.1%) was not the goal of this study, we show that high-field SABRE can be efficient and broadly applicable for direct hyperpolarization of 19F spins.
KW - N-15 HYPERPOLARIZATION
KW - SPIN HYPERPOLARIZATION
KW - TRACE ANALYSIS
KW - SABRE
KW - EFFICIENT
KW - METRONIDAZOLE
KW - FIELD
KW - PARAHYDROGEN
KW - CATALYSTS
KW - MIXTURES
UR - http://www.scopus.com/inward/record.url?scp=85070849335&partnerID=8YFLogxK
U2 - 10.1021/acs.jpclett.9b01505
DO - 10.1021/acs.jpclett.9b01505
M3 - Article
C2 - 31291106
AN - SCOPUS:85070849335
VL - 10
SP - 4229
EP - 4236
JO - Journal of Physical Chemistry Letters
JF - Journal of Physical Chemistry Letters
SN - 1948-7185
IS - 15
ER -
ID: 21336802