Quantitative quantum mechanical approach to SABRE hyperpolarization at high magnetic fields.

Area of Science:

• Nuclear Magnetic Resonance (NMR) Spectroscopy
• Quantum Chemistry
• Chemical Physics

Background:

• Signal Amplification by Reversible Exchange (SABRE) enhances NMR signals using parahydrogen.
• High-field SABRE utilizes NMR excitation schemes for spin order transfer.
• Substrate modification is avoided; spin order transfers in a transient complex.

Purpose of the Study:

• To develop a quantitative theoretical model for high-field SABRE experiments.
• To analyze spin dynamics and kinetics within the SABRE complex.
• To understand parahydrogen spin state alteration and its effect on NMR signal enhancement.

Main Methods:

• Theoretical modeling of spin dynamics in the SABRE complex.
• Incorporation of substrate exchange kinetics (free and bound forms).
• Inclusion of parahydrogen spin state evolution and anti-phase spin order formation.

Main Results:

• The model explicitly treats spin evolution coupled with chemical processes.
• It accounts for the conversion of singlet order to anti-phase order.
• Enables quantitative comparison of SABRE schemes with experimental data.

Conclusions:

• The developed model provides a detailed analysis of high-field SABRE.
• It elucidates key factors limiting NMR signal enhancement.
• Facilitates optimization of SABRE experiments for improved sensitivity.