Long-lived polarization protected by symmetry

Feng, Yesu; Theis, Thomas; Wu, T.; Claytor, Kevin; Warren, Warren S.

doi:10.1063/1.4896895

Cited by 42 publications

(66 citation statements)

References 36 publications

(55 reference statements)

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“…The transformation of total spin magnetization into singlet order, and back again, is an important manipulation in the NMR of long-lived states [13,14,15,16,17,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44] and in parahydrogen-enhanced NMR [18,19,20,21,22,45,46,47,48,49].…”

Section: Magnetization To Singlet Ordermentioning

confidence: 99%

“…I examine closely the spin dynamical manipulations of four-spin systems, involving long-lived spin states [13,14,15,16,17] and SABRE (Signal Amplification by Reversible Exchange) experiments [18,19,20,21,22]. Such experiments sometimes involve four-spin-1/2 systems of the type A 2 X 2 (two magnetically equivalent pairs) or AA XX (two chemically equivalent but magnetically inequivalent pairs).…”

Section: Introductionmentioning

confidence: 99%

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Symmetry constraints on spin dynamics: Application to hyperpolarized NMR

Levitt

2016

Journal of Magnetic Resonance

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Spin dynamical evolution is constrained by the symmetries of the spin Hamiltonians that generate the quantum dynamics. The consequences of symmetry-induced constraints are examined for some common hyperpolarized NMR experiments, including the excitation of singlet order in spin-pair systems, and the transfer of parahydrogen-induced hyperpolarized singlet order to magnetization in systems displaying chemical and magnetic equivalence.

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Section: Magnetization To Singlet Ordermentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Symmetry constraints on spin dynamics: Application to hyperpolarized NMR

Levitt

2016

Journal of Magnetic Resonance

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“…eqn (5)] are compactly represented as the zero-quantum block of the Liouville matrix (thus excluding the non-secular terms):…”

Section: Relaxation Theorymentioning

confidence: 99%

“…Long-lived states (LLS) are configurations of nuclear spin systems that have decay time constants much longer than the conventional spin-lattice relaxation time (T 1 ) under ambient conditions [1][2][3][4][5][6][7][8][9][10][11] . The existence of such states creates many new possibilities in nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) experiments, including the study of slow transport processes such as slow flow and diffusion 12 , as well as the storage of hyperpolarized nuclear spin order for relatively long times 13,14 .…”

Section: Introductionmentioning

confidence: 99%

Prediction of low-field nuclear singlet lifetimes with molecular dynamics and quantum-chemical property surface

Håkansson

2017

Phys. Chem. Chem. Phys.

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Molecular dynamics and quantum chemistry methods are implemented to quantify nuclear spin-1/2 pair singlet-state relaxation rates for three molecular systems at low magnetic field and room temperature. Computational methodology is developed for weak interactions, particularly important for singlet states at low field. These include spin-rotation and spin-internal-motion effects, which describe the coupling of the spin-carrying nuclei to fluctuating local magnetic fields induced by the overall and internal molecular fluctuations, respectively. A high-dimensional tensor property surface using Kriging interpolation is developed to circumvent costly quantum-chemical calculations. Together with the intramolecular dipolar relaxation, all the simulated relaxation mechanisms are accounted for with a common theoretical framework. Comparison with experiment indicates that quantitative accuracy is obtained, sufficient to enable guidance in the molecular design of molecules with long-lived singlet order.

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“…Long-lived states (LLSs) have been implemented experimentally [6][7][8][9][10][11][12][13][14][15] and studied theoretically [16][17][18][19]. For the simplest case of two spin 1 2 particles, the four spin eigenstates can be categorized into two symmetry groups: triplet states and singlet state.…”

Section: Introductionmentioning

confidence: 99%

Dipolar relaxation mechanism of long-lived states of methyl groups

Annabestani

Cory

2017

Quantum Inf Process

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We analyze the symmetry properties of the dipolar Hamiltonian as the main relaxation mechanism responsible for the observed NMR spectra of long-lived states of methyl groups. Long-lived states exhibit relaxation times that are considerably longer than the spin-lattice relaxation time, T 1 . The analysis is complementary to previous studies and provides insight into the relaxation mechanism of long-lived states by focusing exclusively on the symmetry of the spin Hamiltonian. Our study shows that the dipole-dipole coupling between protons of a methyl group and between the protons and an external spin are both symmetry breaking interactions that can lead to relaxation pathways that transform the polarization from symmetry order to Zeeman order. The net contribution of the internal dipolar interaction to the NMR observation of long-lived states is zero. Our calculation is in good agreement with the reported features of the observed spectra and previous theoretical studies.

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Long-lived polarization protected by symmetry

Cited by 42 publications

References 36 publications

Symmetry constraints on spin dynamics: Application to hyperpolarized NMR

Symmetry constraints on spin dynamics: Application to hyperpolarized NMR

Prediction of low-field nuclear singlet lifetimes with molecular dynamics and quantum-chemical property surface

Dipolar relaxation mechanism of long-lived states of methyl groups

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