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Double nutation cross-polarization between heteronuclear spins in solids
1Division of Chemistry, Graduate School of Science, Kyoto University, 606-8502 Kyoto, Japan. takezo@kuchem.kyoto-u.ac.jp.
Physical Chemistry Chemical Physics : PCCP
|May 3, 2023
Summary
We introduce DOuble NUTation (DONUT) cross-polarization for enhanced magnetization transfer in solid-state NMR. This novel technique explores a new nutation frame, enabling efficient spin state exchange.
Area of Science:
- Solid-state Nuclear Magnetic Resonance (NMR)
- Quantum Spin Dynamics
Background:
- Cross-polarization (CP) is crucial for magnetization transfer between nuclear spin species.
- Conventional CP methods have limitations in exploring complex spin interactions.
Purpose of the Study:
- To investigate a novel cross-polarization technique called DOuble NUTation (DONUT).
- To explore magnetization transfer in the unexplored nutation frame.
- To compare DONUT CP with conventional CP schemes.
Main Methods:
- Employing radiofrequency irradiation for simultaneous nutations around orthogonal axes.
- Utilizing the nutation frame, an interaction frame defined by the nutation Hamiltonian.
- Demonstrating DONUT CP in polycrystalline samples (adamantane, glycine, histidine).
Main Results:
- DONUT CP effectively transfers magnetization by developing zero-quantum or double-quantum secular components.
- Observed flip-flop or flop-flop exchange of spin states.
- Examined spectral folding under magic-angle spinning and magnetization buildup kinetics.
Conclusions:
- DONUT CP offers a new paradigm for polarization transfer in solid-state NMR.
- Introduced the concept of spin relaxation in the nutation frame.
- DONUT CP shows potential for enhanced sensitivity and broader applicability in NMR studies.
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