Decoupling-induced recoupling in multiple-quantum magic-angle-spinning NMR spectra of quadrupolar nuclei

2000 ◽  
Vol 322 (6) ◽  
pp. 513-519 ◽  
Author(s):  
Gang Wu
Keyword(s):  
Nmr Spectra ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Quadrupolar Nuclei ◽  
Multiple Quantum ◽  
Angle Spinning

A Comparison of Strategies for Obtaining High-Resolution NMR Spectra of Quadrupolar Nuclei

1996 ◽  
Vol 51 (5-6) ◽  
pp. 321-329 ◽  
Author(s):  
R. E. Youngman ◽  
U. Werner-Zwanziger ◽  
J. W. Zwanziger
Keyword(s):  
High Resolution ◽  
Nmr Spectra ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Quadrupolar Nuclei ◽  
Multiple Quantum ◽  
Oxide Glasses ◽  
High Resolution Nmr ◽  
Angle Spinning ◽  
Nmr Methods

Abstract A comparison of high-resolution NMR methods for quadrupolar nuclei is presented. The samples studied are pure and modified boron oxide glasses, and the boron NMR spectra are recorded using three different experiments capable of high resolution: Double Rotation, Dynamic Angle Spinning, and Multiple-Quantum Magic Angle Spinning. Resolution of the similar ring and nonring boron sites in these glasses, in the presence of disorder, provides a realistic study of the strengths and limitations of these experiments. Conclusions about the relative applicability of these experiments in different situations are presented.

23Na magic-angle spinning and double-rotation NMR study of solid forms of sodium valproate

2014 ◽  
Vol 92 (1) ◽  
pp. 9-15 ◽  
Author(s):  
Nuiok M. Dicaire ◽  
Frédéric A. Perras ◽  
David L. Bryce
Keyword(s):  
Solid State ◽  
Sodium Valproate ◽  
Nmr Spectra ◽  
Structural Information ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Multiple Quantum ◽  
Asymmetric Unit ◽  
Nmr Study ◽  
Angle Spinning

Sodium valproate is a pharmaceutical with applications in the treatment of epilepsy, bipolar disorder, and other ailments. Sodium valproate can exist in many hydrated and acid-stabilized forms in the solid state, and it can be difficult to obtain precise structural information about many of these. Here, we present a 13C and 23Na solid-state NMR study of several forms of sodium valproate, only one of which has been previously structurally characterized by single-crystal X-ray diffraction. 23Na magic-angle spinning (MAS), double-rotation (DOR), and multiple-quantum magic-angle spinning (MQMAS) NMR spectra are shown to provide useful information on the number of molecules in the asymmetric unit, the local coordination geometry of the sodium cations, and the presence of amorphous phases. Two previously identified forms are shown to be highly similar, or identical, according to the 23Na NMR data. The utility of carrying out both DOR and MQMAS NMR experiments to identify all crystallographically unique sites is demonstrated. 13C cross-polarization MAS NMR spectra also provide complementary information on the number of molecules in the asymmetric unit and the crystallinity of the sample.

Multiple-quantum magic-angle spinning and dynamic-angle spinning NMR spectroscopy of quadrupolar nuclei

1997 ◽  
Vol 8 (1) ◽  
pp. 1-16 ◽  
Author(s):  
S.H. Wang ◽  
Z. Xu ◽  
J.H. Baltisberger ◽  
L.M. Bull ◽  
J.F. Stebbins ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Quadrupolar Nuclei ◽  
Multiple Quantum ◽  
Angle Spinning ◽  
Dynamic Angle

Improved Excitation Schemes for Multiple-Quantum Magic-Angle Spinning for Quadrupolar Nuclei Designed Using Optimal Control Theory

2005 ◽  
Vol 127 (40) ◽  
pp. 13768-13769 ◽  
Author(s):  
Thomas Vosegaard ◽  
Cindie Kehlet ◽  
Navin Khaneja ◽  
Steffen J. Glaser ◽  
Niels Chr. Nielsen
Keyword(s):  
Optimal Control ◽  
Control Theory ◽  
Optimal Control Theory ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Quadrupolar Nuclei ◽  
Multiple Quantum ◽  
Angle Spinning
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