Multiple-Quantum Cross-Polarization and Two-Dimensional MQMAS NMR of Quadrupolar Nuclei

Ashbrook, Sharon E.; Wimperis, Stephen

doi:10.1006/jmre.2000.2174

Cited by 50 publications

(34 citation statements)

References 45 publications

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“…On the simplest level, the detection of a cross-polarization signal indicates a spatial proximity (i.e., a significant nonzero dipolar coupling) between two heteronuclei. For example, the demonstration of cross-polarization from 23 Na to all three types of 31 (79,80). Two resonances are observed in the conventional MAS spectrum, whereas only one (Al-O-H) is present in the CP MAS spectrum, as shown in Fig.…”

Section: Uses Of Cross-polarizationmentioning

confidence: 90%

“…4.6 (79). Similarly, only one of the three resonances in the 17 O spectrum of talc is observed when cross-polarization (from 1 H) is employed, selectively exciting the hydroxyl oxygen (80) (81) on aluminas. Kirkpatrick (82) followed the hydration of albite by 27 Al NMR, using cross-polarization to select the hydration products from the starting materials.…”

Section: Uses Of Cross-polarizationmentioning

confidence: 94%

“…4.9(a), which, if applied in isolation, would refocus the heteronuclear dipolar interaction and the chemical shift anisotropy. If, however, a 180°F igure 4.8 A five-quantum cross-polarized MQMAS spectrum, where a 1 H- 27 Al dipolar coupling is observed between all three tetrahedrally coordinated Al species in AlMePO-␤, a novel microporous material (80 ). pulse is also applied to a dipolar-coupled partner, S, at the same time as that applied to I, proper refocusing of the heteronuclear dipolar interaction is prevented and, consequently, the echo intensity at time t ϭ 2 is diminished.…”

Section: Sedor Redor and Tedormentioning

confidence: 97%

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Structural information from quadrupolar nuclei in solid state NMR

Ashbrook

Duer

2006

Concepts Magnetic Resonance

146

262

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Solid-state NMR has become the method of choice for determining details of molecular-level structure in heterogeneous systems. Though spin-1/2 nuclei still form the core of most such studies, quadrupolar nuclei are increasingly being used. This review assesses what is currently possible, from achieving high-resolution spectra for quadrupolar nuclei (a prerequisite for most structure determination work), to forming correlation spectra which give qualitative details of spatial proximity of nuclei and the determination of internuclear distances, between quadrupolar spins and quadrupolar and spin-1/2 nuclei. Examples are given of each method discussed, and the advantages and disadvantages of the various experiments for different possible applications are assessed.

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Section: Uses Of Cross-polarizationmentioning

confidence: 90%

Section: Uses Of Cross-polarizationmentioning

confidence: 94%

Section: Sedor Redor and Tedormentioning

confidence: 97%

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Structural information from quadrupolar nuclei in solid state NMR

Ashbrook

Duer

2006

Concepts Magnetic Resonance

146

262

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“…Various radiofrequency (RF) pulse sequences have been suggested [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20], including shaped pulses [21,22], optimization of MQ coherence transfers [23][24][25], factors limiting the resolution [26][27][28][29][30], spectral editing [31], correlation between satellite and central transitions [32], suppression of sidebands by variable-speed MAS [33], spectra simulation [34][35][36], quantification of spectra with numerical simulation [37], lineshape analysis [38][39][40], and disorder analysis [41]. This method has been applied to the characterization of: (i) meso-and microporous materials such as alumina [42], aluminophosphate [11,12,[43][44][45]...…”

Section: Introductionmentioning

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

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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)

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“…Besides standard methodology, a variety of modern techniques like multi-quantum magic angle spinning NMR have been applied to diverse oxidic scandium compounds [33][34][35][36] in order to get more detailed structural information on these materials, e. g. differentiation of the scandium sites in organically templated scandium fluorophosphate frameworks [37], to work out the influence of the coordination number on the isotropic chemical shift in stabilized zirconia [38] and to systemize the 45 Sc chemical shifts in several basic inorganic scandium compounds [39].…”

Section: Introductionmentioning

confidence: 99%

⁴⁵Sc Solid State NMR Spectroscopy – A Complementary Tool to X‐ray Crystallography for Structure Determination of Intermetallic Compounds

Eckert

Pöttgen

2010

Zeitschrift anorg allge chemie

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45Sc solid state NMR spectroscopy is a useful complementary tool to X‐ray crystallography for structure determination. Recent developments in the field of intermetallic scandium compounds are reviewed. The structural topics concern defect formation, structural disorder, superstructure formation, as well as the detection of multiple scandium sites. To address questions of this kind, high‐resolution 45Sc NMR spectroscopic techniques were established as a new structural tool for the quantification of the local coordination scandium environments and the detailed characterization of their internal NMR interaction parameters. Owing to the moderately sized nuclear electric quadrupole moment of 45Sc, the magic‐angle spinning spectra are affected both by first‐ and second‐order quadrupolar perturbations, which can be analyzed and quantified by fast magic angle spinning, assisted by lineshape simulations. The resolution can be further improved by correlating triple quantum (TQ) with single quantum coherences. Using this 2D NMR spectroscopic methodology, the effects of magnetic shielding and second‐order quadrupolar perturbations on the MAS NMR lineshape can be separated, enabling a more precise experimental characterization of electric field gradients present at the 45Sc nuclei. Structure validation includes the precise measurement of these parameters and comparison with quantum mechanically calculated values based on the atomic positions. In this regard, satisfactory results were obtained using the WIEN2k program.

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Multiple-Quantum Cross-Polarization and Two-Dimensional MQMAS NMR of Quadrupolar Nuclei

Cited by 50 publications

References 45 publications

Structural information from quadrupolar nuclei in solid state NMR

Structural information from quadrupolar nuclei in solid state NMR

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

⁴⁵Sc Solid State NMR Spectroscopy – A Complementary Tool to X‐ray Crystallography for Structure Determination of Intermetallic Compounds

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Multiple-Quantum Cross-Polarization and Two-Dimensional MQMAS NMR of Quadrupolar Nuclei

Cited by 50 publications

References 45 publications

Structural information from quadrupolar nuclei in solid state NMR

Structural information from quadrupolar nuclei in solid state NMR

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

45Sc Solid State NMR Spectroscopy – A Complementary Tool to X‐ray Crystallography for Structure Determination of Intermetallic Compounds

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⁴⁵Sc Solid State NMR Spectroscopy – A Complementary Tool to X‐ray Crystallography for Structure Determination of Intermetallic Compounds