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Magnetometer-Detected Nuclear Magnetic Resonance of Photochemically Hyperpolarized Molecules
Liubov Chuchkova1,2, Sven Bodenstedt3, Román Picazo-Frutos1,2
1Institut für Physik, Johannes Gutenberg Universität-Mainz, 55128 Mainz, Germany.
The Journal of Physical Chemistry Letters
|July 24, 2023
Summary
Low-field nuclear magnetic resonance (NMR) can now detect spin-polarized molecules using light. This new magnetometer-detected photo-CIDNP method offers enhanced sensitivity and narrower spectral lines for studying chemical reactions.
Area of Science:
- Physical Chemistry
- Magnetic Resonance Spectroscopy
- Chemical Physics
Background:
- Photochemically induced dynamic nuclear polarization (photo-CIDNP) is a technique for ordering nuclear spins using light.
- Conventional photo-CIDNP detection relies on high-field Nuclear Magnetic Resonance (NMR) spectroscopy (above 0.1 T).
- There is a need for sensitive, low-field detection methods for photo-CIDNP to study spin-chemistry processes.
Purpose of the Study:
- To demonstrate in situ low-field photo-CIDNP measurements.
- To detect hyperpolarized nuclear magnetization using atomic magnetometers.
- To investigate the potential of this technique for observing spin-chemistry in ambient magnetic fields.
Main Methods:
- Utilized a magnetically shielded, fast-field-cycling NMR setup.
- Detected Larmor precession signals via atomic magnetometers.
- Performed measurements on solutions with millimolar concentrations of photochemically polarized molecules.
Main Results:
- Successfully detected hyperpolarized 1H magnetization using pulse-acquired NMR spectroscopy at low fields.
- Observed NMR line widths approximately 5 times narrower than typical high-field NMR.
- Demonstrated a reduction in the transverse relaxation time constant (T2*) by about 10% upon light irradiation during acquisition.
Conclusions:
- Magnetometer-detected photo-CIDNP spectroscopy enables straightforward observation of spin-chemistry processes in ambient magnetic fields (nT to mT range).
- This technique offers enhanced sensitivity and resolution compared to conventional high-field NMR detection.
- The method holds potential for various applications in studying light-induced chemical reactions and spin dynamics.
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