Theoretical and experimental study of quadrupolar echoes for half-integer spins in static solid-state NMR

Bodart, Philippe R.; Amoureux, Jean‐Paul; Dumazy, Y; Lefort, Ronan

doi:10.1080/00268970009483360

Cited by 67 publications

(47 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…echo [100][101][102][103][104], which is located at t 2 = t 1 and whose amplitude is modulated neither in phase nor in amplitude, the MQ-MAS echo and anti-echo amplitudes are phase-modulated by exp[−t 2 ω F1 (I p)] with [105] …”

Section: Theorymentioning

confidence: 99%

Procedures for Labeling the High-Resolution Axis of Two-Dimensional MQ-MAS NMR Spectra of Half-Integer Quadrupole Spins

Millot

Man

2002

Solid State Nuclear Magnetic Resonance

View full text Add to dashboard Cite

The increasing development and application of the multiple-quantum MAS NMR for halfinteger quadrupole spins has led to various RF pulse sequences for improving the excitation of multiple-quantum coherences and their conversion to single-quantum coherences. As a result, several conventions for labeling the F1 dimension of a 2D MQ-MAS spectrum appear in the literature. The corresponding relations for extracting the isotropic chemical shift, the quadrupole coupling constant, and the asymmetry parameter from experimental data are not always provided. We analyze these various conventions systematically and propose a new one, similar to that introduced by J.-P. Amoureux and C. Fernandez (2000, Solid State NMR 10, 339-343). These various conventions are illustrated with 27 Al (I = 5/2) nuclei in aluminum acetylacetonate Al(CH 3 COCHCOCH 3 ) 3 . Another experimental problem often met, the aliasing of peaks in the 2D spectrum, is analyzed and illustrated with 27 Al (I = 5/2) in NH 4 Y zeolite and 23 Na (I = 3/2) in sodium pyrophosphate Na 4 P 2 O 7 . © 2002 Elsevier Science (USA)

show abstract

Section: Theorymentioning

confidence: 99%

Procedures for Labeling the High-Resolution Axis of Two-Dimensional MQ-MAS NMR Spectra of Half-Integer Quadrupole Spins

Millot

Man

2002

Solid State Nuclear Magnetic Resonance

View full text Add to dashboard Cite

show abstract

“…Pulses in the spin-echo sequence were optimized to reproduce the powder line shapes accurately. 28 The echo delays in QCPMG trains were set between 100 and 500 µs, and from 40 to 80 echoes were usually accumulated. In situations when the whole spectral range could not be excited in a single experiment (all compounds except K 2 SO 4 ), the spectra were obtained from several equally spaced offsets.…”

Section: Introductionmentioning

confidence: 99%

High Field ³³S Solid State NMR and First-Principles Calculations in Potassium Sulfates

et al. 2009

View full text Add to dashboard Cite

Vous avez des questions? Nous pouvons vous aider. Pour communiquer directement avec un auteur, consultez la première page de la revue dans laquelle son article a été publié afin de trouver ses coordonnées. Si vous n'arrivez pas à les repérer, communiquez avec nous à PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. Questions? Contact the NRC Publications Archive team atPublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. If you wish to email the authors directly, please see the first page of the publication for their contact information. NRC Publications Archive Archives des publications du CNRCThis publication could be one of several versions: author's original, accepted manuscript or the publisher's version. / La version de cette publication peut être l'une des suivantes : la version prépublication de l'auteur, la version acceptée du manuscrit ou la version de l'éditeur. NRC Publications Record / Notice d'Archives des publications de CNRC:http://nparc.cisti-icist.nrc-cnrc.gc.ca/eng/view/object/?id=0b178185-620e-4262-8966-6e518a9bdcdf http://nparc.cisti-icist.nrc-cnrc.gc.ca/fra/voir/objet/?id=0b178185-620e-4262-8966-6e518a9bdcdf High Field S Solid State NMR and First-Principles Calculations in Potassium SulfatesIgor Moudrakovski,* Stephen Lang, Serguei Patchkovskii, and John Ripmeester Steacie Institute for Molecular Sciences, National Research Council, 100 Sussex DriVe, Ottawa, K1A 0R6, Ontario, Canada ReceiVed: August 25, 2009; ReVised Manuscript ReceiVed: October 16, 2009 A set of potassium sulfates presenting a variety of sulfur environments (K 2 SO 4 , KHSO 4 ,K 2 S 2 O 7 , and K 2 S 2 O 8 ) has been studied by 33 S solid state NMR at 21 T. Low natural abundance (0.75%) and small gyromagnetic ratio of 33 S presented a serious challenge even at such a high magnetic field. Nevertheless, using the QCPMG technique we were able to obtain good signals from the sites with C Q values approaching 16 MHz. Assignment of the sites and the relative orientations of the EFG tensors were assisted by quantum mechanical calculations using the Gaussian 98 and CASTEP packages. The Gaussian 98 calculations were performed using the density functional method and gauge independent atomic orbitals on molecular clusters of about 100-120 atoms. The CASTEP calculations utilized periodic boundary conditions and a gauge-including projector augmentedwave pseudopotential approach. Although only semiquantitative agreement is observed between the experimental and calculated parameters, the calculations are a very useful aid in the interpretation of experimental data.

show abstract

“…These measurements were performed using a Bruker 5 mm static horizontal solenoid design probe (at 9.4 T), and a home-built, balanced-circuit design 7.5 mm static horizontal solenoid probe (at 18.8 T). All static 93 Nb data were acquired with the solid echo θ -τ -θ -τ -(acquire) (θ ≈ π/4) experiment with an extended phase cycle to capture undistorted echoes with minimal influences from residual echo tails and finite pulse widths 28,29 . 'Non-selective' (solution) π/2 pulse widths of 8 -10 μs were calibrated on a saturated K[NbCl6]/CH3CN solution from which 'selective' (solid) θ pulses of 0.8 -1.0 μs were employed in the solid echo measurements.…”

Section: Solid State Nmrmentioning

confidence: 99%

The Crystal Structure of Ba₃Nb₂O₈ Revisited: A Neutron Diffraction and Solid-State NMR Study

et al. 2017

View full text Add to dashboard Cite

ABSTRACT:The structure of Ba3Nb2O8 has been investigated using high resolution neutron powder diffraction. Our results show that whilst the structure has some features in common with the 9R perovskite and palmierite structures, it is a new and distinct structure. It is shown to follow a (chh)(hhc)(chh) sequence with BaO3- packing layers and is a cation and aniondeficient 9H perovskite polytype. Nb atoms occupy octahedral sites with vacancies between hexagonal close-packed layers. Isolated, corner-sharing and face-sharing Nb-O octahedra all occur within the unit cell. The identification of purely octahedral Nb is supported by solid state 93 Nb wideline NMR measurements. A two-component line shape was detected: a narrow featureless resonance with an isotropic chemical shift of δiso -928 ± 5 ppm consistent with regular Nb octahedra, and a much broader featureless resonance with an approximate isotropic chemical shift in the range δiso ~-944 --937 ± 10 ppm consistent with Nb octahedra influenced by O vacancies. These are both characteristic of six-fold oxo-coordinated Nb environments. The highly distorted octahedral environments in Ba3Nb2O8 make it a potential candidate for dielectric and photocatalytic applications.

show abstract

Theoretical and experimental study of quadrupolar echoes for half-integer spins in static solid-state NMR

Cited by 67 publications

References 18 publications

Procedures for Labeling the High-Resolution Axis of Two-Dimensional MQ-MAS NMR Spectra of Half-Integer Quadrupole Spins

Procedures for Labeling the High-Resolution Axis of Two-Dimensional MQ-MAS NMR Spectra of Half-Integer Quadrupole Spins

High Field ³³S Solid State NMR and First-Principles Calculations in Potassium Sulfates

The Crystal Structure of Ba₃Nb₂O₈ Revisited: A Neutron Diffraction and Solid-State NMR Study

Contact Info

Product

Resources

About

Theoretical and experimental study of quadrupolar echoes for half-integer spins in static solid-state NMR

Cited by 67 publications

References 18 publications

Procedures for Labeling the High-Resolution Axis of Two-Dimensional MQ-MAS NMR Spectra of Half-Integer Quadrupole Spins

Procedures for Labeling the High-Resolution Axis of Two-Dimensional MQ-MAS NMR Spectra of Half-Integer Quadrupole Spins

High Field 33S Solid State NMR and First-Principles Calculations in Potassium Sulfates

The Crystal Structure of Ba3Nb2O8 Revisited: A Neutron Diffraction and Solid-State NMR Study

Contact Info

Product

Resources

About

High Field ³³S Solid State NMR and First-Principles Calculations in Potassium Sulfates

The Crystal Structure of Ba₃Nb₂O₈ Revisited: A Neutron Diffraction and Solid-State NMR Study