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High-Temperature and High-Pressure In situ Magic Angle Spinning Nuclear Magnetic Resonance Spectroscopy
Published on: October 9, 2020
Decoupling and recoupling using continuous-wave irradiation in magic-angle-spinning solid-state NMR: a unified
Matthias Ernst1, Ago Samoson, Beat H Meier
1Physical Chemistry, Eidgenössische Technische Hochschule (ETH) Zurich, CH-8093 Zürich, Switzerland. maer@nmr.phys.chem.ethz.ch
The Journal of Chemical Physics
|August 27, 2005
Summary
This study unifies descriptions of nuclear magnetic resonance (NMR) experiments with multiple time-dependent perturbations using bimodal Floquet theory. The approach yields an effective Hamiltonian, generalizing average Hamiltonian theory for complex NMR applications.
Area of Science:
- Nuclear Magnetic Resonance (NMR) Spectroscopy
- Quantum Mechanics
- Physical Chemistry
Background:
- NMR experiments frequently employ multiple time-dependent coherent perturbations with incommensurable frequencies.
- Existing theories may not fully capture the complexity of such multi-frequency perturbations.
Purpose of the Study:
- To develop a unified theoretical framework for NMR experiments involving two or more time-dependent perturbations.
- To generalize average Hamiltonian theory to handle multiple incommensurate time dependencies.
Main Methods:
- Application of bimodal Floquet theory.
- Utilization of van Vleck-Primas perturbation theory.
- Development of a time-independent effective Hamiltonian in Hilbert space.
Main Results:
- A unified description for a broad class of NMR experiments with multiple perturbations.
- The derived effective Hamiltonian simplifies the analysis of complex time-dependent phenomena.
- Third-order perturbation analysis is necessary to explain observed resonance conditions.
Conclusions:
- Bimodal Floquet and van Vleck-Primas theories provide a robust framework for analyzing complex NMR experiments.
- The generalized theory accurately describes phenomena like continuous-wave (cw) radio-frequency irradiation with magic-angle spinning.
- This work advances the understanding and application of advanced NMR techniques, including heteronuclear spin decoupling and recoupling.
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