Journal ArticleDOI
Deuterium quadrupole echo NMR spectroscopy. I. Effects of chemical exchange during single and composite pulses
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TLDR
The effects of chemical exchange during rf pulses on deuterium quadrupole echo spectra have been evaluated numerically for single pulses as well as for Levitt-Suter-Emst composite pulses as mentioned in this paper.About:
This article is published in Journal of Magnetic Resonance.The article was published on 1986-09-01. It has received 48 citations till now. The article focuses on the topics: Pulse sequence & Spin echo.read more
Citations
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Journal ArticleDOI
Sensitivity-Enhanced Quadrupolar-Echo NMR of Half-Integer Quadrupolar Nuclei. Magnitudes and Relative Orientation of Chemical Shielding and Quadrupolar Coupling Tensors
TL;DR: In this article, the second-order quadrupolar line shape for the central transition is split into a comb of sidebands leading to a considerable increase in the sensitivity compared to a conventional QE spectrum.
Journal ArticleDOI
Effects of jump dynamics on solid state nuclear magnetic resonance line shapes and spin relaxation times.
Robert L. Vold,Gina L. Hoatson +1 more
TL;DR: ExPRESS is used to investigate fundamental differences in the mechanism of echo formation in deuteron MAS and quadrupole CPMG experiments, and to illustrate significant differences between these techniques in the context of high spin quadrupolar nuclei.
Journal ArticleDOI
Molecular dynamics from 2H Quadrupolar Carr–Purcell–Meiboom–Gill solid-state NMR spectroscopy
TL;DR: The 2 H quadrupolar Carr-Purcell-Meiboom-Gill (QCPMG) NMR experiment was proposed in this article to obtain detailed information about molecular dynamics in solids.
Journal ArticleDOI
Investigation of multiaxial molecular dynamics by MAS NMR spectroscopy
TL;DR: A Lie algebraic formalism based on the stochastic Liouville-von Neumann equation is developed that allows effects of molecular dynamics to be evaluated during rf pulses and extends the applicability of the formalism to arbitrary multiple pulse experiments.
References
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Book
Principles of high-resolution NMR in solids
Abstract: 1 Introduction.- 2 Nuclear Spin Interactions in Solids.- 2.1 Basic Nuclear Spin Interactions in Solids.- 2.2 Spin Interactions in High Magnetic Fields.- 2.3 Transformation Properties of Spin Interactions in Real Space.- 2.4 Powder Spectrum Line Shape.- 2.5 The NMR Spectrum. Lineshapes and Moments.- 2.6 Magic Angle Spinning (MAS).- 2.7 Rapid Anisotropic Molecular Rotation.- 2.8 Line Shapes in the Presence of Molecular Reorientation.- 3 Multiple-Pulse NMR Experiments.- 3.1 Idealized Multiple-Pulse Sequences.- 3.2 The Four-Pulse Sequence (WHH-4).- 3.3 Coherent Averaging Theory.- 3.4 Application of Coherent Averaging Theory to Multiple-Pulse Sequences.- 3.5 Arbitrary Rotations and Finite Pulse Width in Multiple-Pulse Experiments.- 3.6 Second Averaging.- 3.7 The Influence of Pulse Imperfections on Multiple-Pulse Experiments.- 3.8 Resolution of Multiple-Pulse Experiments.- 3.9 Magic Angle Rotating Frame Line Narrowing Experiments.- 3.10 Modulation Induced Line Narrowing.- 3.11 Applications of Multiple-Pulse Experiments.- 4 Double Resonance Experiments.- 4.1 Basic Principles of Double Resonance Experiments.- 4.2 Cross-Polarization of Dilute Spins.- 4.3 Cross-Polarization Dynamics.- 4.4 Spin-Decoupling Dynamics.- 4.5 Application of Cross-Polarization Experiments.- 5 Two-Dimensional NMR Spectroscopy.- 5.1 Basic Principles of 2 D-Spectroscopy.- 5.2 2D-Spectroscopy of 13C-1H Interactions in Solids.- 5.3 Applications of 2D-Spectroscopy.- 6 Multiple-Quantum NMR Spectroscopy.- 6.1 Double-Quantum Decoupling.- 6.2 The Three-Level System Double Quantum Coherence.- 6.3 Multiple-Quantum Coherence.- 6.4 Selective Multiple-Quantum Coherence.- 6.5 Double-Quantum Cross-Polarization.- 7 Magnetic Shielding Tensor.- 7.1 Ramsey's Formula.- 7.2 Approximate Calculations of the Shielding Tensor.- 7.3 Proton Shielding Tensors.- 7.4 19F Shielding Tensors.- 7.5 13C Shielding Tensors.- 7.6 Other Shielding Tensors.- 8 Spin-Lattice Relaxation.- 8.1 Spin-Lattice Relaxation in the Weak Collision Limit.- 8.2 Spin-Lattice Relaxation in Multiple-Pulse Experiments.- 8.3 Application of Multiple-Pulse Experiments to the Investigation of Spin-Lattice Relaxation.- 8.4 Spin-Lattice Relaxation in Dilute Spin Systems.- 8.5 Selective Excitation and Spectral Diffusion.- 9 Appendix.- A Irreducible Tensor Representation of Spin Interactions.- B Rotations.- C General Line Shape Theory.- D Homogeneous, Inhomogeneous and Heterogeneous Lineshapes.- E Lineshape and Relaxation due to Fluctuating Chemical Shift Tensors.- F Time Evolution and Magnus Expansion.- G Coherent Versus Secular Averaging Theory.- H Applications of Average Hamiltonian Theory.- I Relaxation Theory.- 10 References.- 11 Subject Index.
Journal ArticleDOI
Quadrupolar echo deuteron magnetic resonance spectroscopy in ordered hydrocarbon chains
TL;DR: In this paper, the quadrupolar spin echo from deuterons in ordered hydrocarbon systems is shown to provide a much more reliable spectrum than the conventional free induction decay Fourier transform.
Journal ArticleDOI
The description of membrane lipid conformation, order and dynamics by 2H-NMR
Journal ArticleDOI
Selective excitation and detection in multilevel spin systems: Application of single transition operators
A. Wokaun,R. R. Ernst +1 more
TL;DR: In this article, an alternative definition of single transition operators is given for the description of selective excitation and detection experiments in multilevel spin systems, which has the virtues of a simple physical interpretation and easy application to arbitrarily complicated systems.
Journal ArticleDOI
Operator formalism for double quantum NMR
Shimon Vega,Alexander Pines +1 more
Abstract: An operator formalism is presented which conveniently treats the interaction of a spin‐1 nucleus with a weak radio frequency field. The Hamiltonian in the rotating frame is H=−Δω Iz−ω1Ix+(1/3) ωQ[3 I2z−I (I+1)], where Δω is the resonance offset (Δω=ω0−ω), ω1 is the intensity of the rf field, and ωQ is the quadrupolar splitting. Nine fictitious spin−1/2 operators, Ip,i where p=x,y,z and i=1,2,3, are defined where p refers to the transition between two of the levels and i the Cartesian component. The operators, which are the generators of the group SU (3), satisfy spin‐1/2 commutation relations [Ip,j, Ip,k]=i Ip,l, where j,k,l=1,2,3 or cyclic permutation. Thus each p defines a three‐dimensional space termed p space. For irradiation near one of the quadrupolar satellites, for example, Δω=ωQ+δω with δω, ω1≪ωQ, it is shown that the effective Hamiltonian can be written H?−δωIx,3−√2 ω1Ix,1, i.e., a fictitious spin‐1/2 Hamiltonian in x space with effective magnetogyric ratio γ along the 3 (resonance offset) axis and √2 γ along the 1 (rf field) axis. For irradiation near the center we can effect double quantum transitions between m=±1. The formalism allows us to write the effective operators for these transitions. For example, if we take Δω=δω again with δω, ω1≪ωQ we find the effective double quantum (DQ) Hamiltonian H?−2 δω Iz,1−(ω21/ωQ) Iz,3. Thus the z space is referred to as the double quantum frame with effective magnetogyric ratio 2γ along the 1 (resonance offset) axis and (ω1/ωQ) γ along the 3 (rf field) axis. The limiting expressions are compared with exact calculations for arbitrary ω1 done by high speed computer. The theory is applied to various cases of irradiation including our previously reported technique of Fourier transform double quantum NMR. Various pulse sequences for preparing, storing, and maintaining the evolution of double quantum coherence are analyzed for single crystal and polycrystalline samples. Finally, the effects of rf phase on the double quantum phase are presented briefly, and the possibility of double quantum spin locking is analyzed.