Nuclear spin hyperpolarization of the solvent using signal amplification by reversible exchange (SABRE)

Karlos X. Moreno, Khaled Nasr, Mark Milne, A. Dean Sherry, Warren J. Goux

Research output: Contribution to journalArticle

16 Citations (Scopus)

Abstract

Abstract Here we report the polarization of the solvent OH protons by SABRE using standard iridium-based catalysts under slightly acidic conditions. Solvent polarization was observed in the presence of a variety of structurally similar N-donor substrates while no solvent enhancement was observed in the absence of substrate or para-hydrogen (p-H<inf>2</inf>). Solvent polarization was sensitive to the polarizing field and catalyst:substrate ratio in a manner similar to that of substrate protons. SABRE experiments with pyridine-d<inf>5</inf> suggest a mechanism where hyperpolarization is transferred from the free substrate to the solvent by chemical exchange while measured hyperpolarization decay times suggest a complimentary mechanism which occurs by direct coordination of the solvent to the catalytic complex. We found the solvent hyperpolarization to decay nearly 3 times more slowly than its characteristic spin-lattice relaxation time suggesting that the hyperpolarized state of the solvent may be sufficiently long lived (∼20 s) to hyperpolarize biomolecules having exchangeable protons. This route may offer future opportunities for SABRE to impact metabolic imaging.

Original languageEnglish (US)
Article number5646
Pages (from-to)15-23
Number of pages9
JournalJournal of Magnetic Resonance
Volume257
DOIs
StatePublished - Jun 1 2015

Fingerprint

nuclear spin
Amplification
Substrates
Protons
Polarization
protons
polarization
para hydrogen
catalysts
Iridium
Catalysts
Spin-lattice relaxation
Biomolecules
decay
iridium
spin-lattice relaxation
Relaxation time
Hydrogen
pyridines
relaxation time

Keywords

  • Chemical exchange
  • Hyperpolarization
  • Iridium catalyst
  • MR imaging
  • SABRE
  • Solvent enhancement

ASJC Scopus subject areas

  • Nuclear and High Energy Physics
  • Biochemistry
  • Biophysics
  • Condensed Matter Physics

Cite this

Nuclear spin hyperpolarization of the solvent using signal amplification by reversible exchange (SABRE). / Moreno, Karlos X.; Nasr, Khaled; Milne, Mark; Sherry, A. Dean; Goux, Warren J.

In: Journal of Magnetic Resonance, Vol. 257, 5646, 01.06.2015, p. 15-23.

Research output: Contribution to journalArticle

Moreno, Karlos X. ; Nasr, Khaled ; Milne, Mark ; Sherry, A. Dean ; Goux, Warren J. / Nuclear spin hyperpolarization of the solvent using signal amplification by reversible exchange (SABRE). In: Journal of Magnetic Resonance. 2015 ; Vol. 257. pp. 15-23.
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