Limits in Proton Nuclear Singlet-State Lifetimes Measured with para-Hydrogen-Induced Polarization

Yuning Zhang, Xueyou Duan, Pei Che Soon, Vladimír Sychrovský, James Canary, Alexej Jerschow

Research output: Contribution to journalArticle

Abstract

The synthesis of a hyperpolarized molecule was developed, where the polarization and the singlet state were preserved over two controlled chemical steps. Nuclear singlet-state lifetimes close to 6 min for protons are reported in dimethyl fumarate. Owing to the high symmetry (AA′X3X3′ and A2 systems), the singlet-state readout requires either a chemical desymmetrization or a long and repeated spin lock. Using DFT calculations and relaxation models, we further determine nuclear spin singlet lifetime limiting factors, which include the intramolecular dipolar coupling mechanism (proton–proton and proton–deuterium), the chemical shift anisotropy mechanism (symmetric and antisymmetric), and the intermolecular dipolar coupling mechanism (to oxygen and deuterium). If the limit of paramagnetic relaxation caused by residual oxygen could be lifted, the intramolecular dipolar coupling to deuterium would become the limiting relaxation mechanism and proton lifetimes upwards of 26 min could become available in the molecules considered here (dimethyl maleate and dimethyl fumarate).

Original languageEnglish (US)
Pages (from-to)2967-2971
Number of pages5
JournalChemPhysChem
DOIs
StatePublished - Oct 5 2016

Fingerprint

para hydrogen
Deuterium
Protons
Hydrogen
Polarization
Oxygen
life (durability)
Molecules
protons
Chemical shift
polarization
Discrete Fourier transforms
deuterium
Anisotropy
maleates
oxygen
nuclear spin
chemical equilibrium
readout
molecules

Keywords

  • chemical shift anisotropy
  • dimethyl fumarate
  • hyperpolarization
  • paramagnetic relaxation
  • singlet lifetime limits

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Physical and Theoretical Chemistry

Cite this

Limits in Proton Nuclear Singlet-State Lifetimes Measured with para-Hydrogen-Induced Polarization. / Zhang, Yuning; Duan, Xueyou; Soon, Pei Che; Sychrovský, Vladimír; Canary, James; Jerschow, Alexej.

In: ChemPhysChem, 05.10.2016, p. 2967-2971.

Research output: Contribution to journalArticle

Zhang, Yuning ; Duan, Xueyou ; Soon, Pei Che ; Sychrovský, Vladimír ; Canary, James ; Jerschow, Alexej. / Limits in Proton Nuclear Singlet-State Lifetimes Measured with para-Hydrogen-Induced Polarization. In: ChemPhysChem. 2016 ; pp. 2967-2971.
@article{cc8e48787e4544bdb21b417a3fab82cf,
title = "Limits in Proton Nuclear Singlet-State Lifetimes Measured with para-Hydrogen-Induced Polarization",
abstract = "The synthesis of a hyperpolarized molecule was developed, where the polarization and the singlet state were preserved over two controlled chemical steps. Nuclear singlet-state lifetimes close to 6 min for protons are reported in dimethyl fumarate. Owing to the high symmetry (AA′X3X3′ and A2 systems), the singlet-state readout requires either a chemical desymmetrization or a long and repeated spin lock. Using DFT calculations and relaxation models, we further determine nuclear spin singlet lifetime limiting factors, which include the intramolecular dipolar coupling mechanism (proton–proton and proton–deuterium), the chemical shift anisotropy mechanism (symmetric and antisymmetric), and the intermolecular dipolar coupling mechanism (to oxygen and deuterium). If the limit of paramagnetic relaxation caused by residual oxygen could be lifted, the intramolecular dipolar coupling to deuterium would become the limiting relaxation mechanism and proton lifetimes upwards of 26 min could become available in the molecules considered here (dimethyl maleate and dimethyl fumarate).",
keywords = "chemical shift anisotropy, dimethyl fumarate, hyperpolarization, paramagnetic relaxation, singlet lifetime limits",
author = "Yuning Zhang and Xueyou Duan and Soon, {Pei Che} and Vladim{\'i}r Sychrovsk{\'y} and James Canary and Alexej Jerschow",
year = "2016",
month = "10",
day = "5",
doi = "10.1002/cphc.201600663",
language = "English (US)",
pages = "2967--2971",
journal = "ChemPhysChem",
issn = "1439-4235",
publisher = "Wiley-VCH Verlag",

}

TY - JOUR

T1 - Limits in Proton Nuclear Singlet-State Lifetimes Measured with para-Hydrogen-Induced Polarization

AU - Zhang, Yuning

AU - Duan, Xueyou

AU - Soon, Pei Che

AU - Sychrovský, Vladimír

AU - Canary, James

AU - Jerschow, Alexej

PY - 2016/10/5

Y1 - 2016/10/5

N2 - The synthesis of a hyperpolarized molecule was developed, where the polarization and the singlet state were preserved over two controlled chemical steps. Nuclear singlet-state lifetimes close to 6 min for protons are reported in dimethyl fumarate. Owing to the high symmetry (AA′X3X3′ and A2 systems), the singlet-state readout requires either a chemical desymmetrization or a long and repeated spin lock. Using DFT calculations and relaxation models, we further determine nuclear spin singlet lifetime limiting factors, which include the intramolecular dipolar coupling mechanism (proton–proton and proton–deuterium), the chemical shift anisotropy mechanism (symmetric and antisymmetric), and the intermolecular dipolar coupling mechanism (to oxygen and deuterium). If the limit of paramagnetic relaxation caused by residual oxygen could be lifted, the intramolecular dipolar coupling to deuterium would become the limiting relaxation mechanism and proton lifetimes upwards of 26 min could become available in the molecules considered here (dimethyl maleate and dimethyl fumarate).

AB - The synthesis of a hyperpolarized molecule was developed, where the polarization and the singlet state were preserved over two controlled chemical steps. Nuclear singlet-state lifetimes close to 6 min for protons are reported in dimethyl fumarate. Owing to the high symmetry (AA′X3X3′ and A2 systems), the singlet-state readout requires either a chemical desymmetrization or a long and repeated spin lock. Using DFT calculations and relaxation models, we further determine nuclear spin singlet lifetime limiting factors, which include the intramolecular dipolar coupling mechanism (proton–proton and proton–deuterium), the chemical shift anisotropy mechanism (symmetric and antisymmetric), and the intermolecular dipolar coupling mechanism (to oxygen and deuterium). If the limit of paramagnetic relaxation caused by residual oxygen could be lifted, the intramolecular dipolar coupling to deuterium would become the limiting relaxation mechanism and proton lifetimes upwards of 26 min could become available in the molecules considered here (dimethyl maleate and dimethyl fumarate).

KW - chemical shift anisotropy

KW - dimethyl fumarate

KW - hyperpolarization

KW - paramagnetic relaxation

KW - singlet lifetime limits

UR - http://www.scopus.com/inward/record.url?scp=84989812375&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84989812375&partnerID=8YFLogxK

U2 - 10.1002/cphc.201600663

DO - 10.1002/cphc.201600663

M3 - Article

SP - 2967

EP - 2971

JO - ChemPhysChem

JF - ChemPhysChem

SN - 1439-4235

ER -