Double-Quantum-Filtered Rotational-Resonance MAS NMR in the Presence of Large Chemical Shielding Anisotropies

2001 ◽  
Vol 152 (1) ◽  
pp. 14-25 ◽  
Author(s):  
Matthias Bechmann ◽  
Xavier Helluy ◽  
Angelika Sebald
Keyword(s):  
Mas Nmr ◽  
Double Quantum ◽  
Chemical Shielding ◽  
Rotational Resonance

13C chemical shielding tensor orientations in a phosphoenolpyruvate moiety from 13C rotational-resonance MAS NMR lineshapes

2004 ◽  
Vol 6 (10) ◽  
pp. 1097-1105 ◽  
Author(s):  
M. Bechmann ◽  
S. Dusold ◽  
A. Sebald ◽  
W.A. Shuttleworth ◽  
D.L. Jakeman ◽  
...  
Keyword(s):  
Mas Nmr ◽  
Chemical Shielding ◽  
Rotational Resonance ◽  
Shielding Tensor

Double-Quantum Filtered MAS NMR in the Presence of Chemical Shielding Anisotropies and Direct Dipolar and JCouplings

2002 ◽  
Vol 21 (1-2) ◽  
pp. 71-85 ◽  
Author(s):  
Matthias Bechmann ◽  
Xavier Helluy ◽  
Claire Marichal ◽  
Angelika Sebald
Keyword(s):  
Mas Nmr ◽  
Double Quantum ◽  
Chemical Shielding

Article

1999 ◽  
Vol 77 (11) ◽  
pp. 1962-1972
Author(s):  
Scott Kroeker ◽  
Roderick E Wasylishen
Keyword(s):  
Nmr Spectra ◽  
Magic Angle Spinning ◽  
Mas Nmr ◽  
Spin Coupling ◽  
Group Symmetry ◽  
Magic Angle ◽  
Chemical Shielding ◽  
Shielding Tensor ◽  
Angle Spinning ◽  
Spin Spin Coupling

Direct NMR observation of copper-63/65 nuclei in solid K3Cu(CN)4 provides the first experimental example of anisotropic copper chemical shielding. Axially symmetric by virtue of the space group symmetry, the shielding tensor spans 42 ppm, with the greatest shielding when the unique axis is perpendicular to the applied magnetic field. The nuclear quadrupole coupling constant is also appreciable, CQ(63Cu) = -1.125 MHz, reflecting a deviation of the Cu(CN)43- anion from pure tetrahedral symmetry. Spin-spin coupling to 13C nuclei in an isotopically enriched sample is quantified by line-shape simulations of both 13C and 63/65Cu magic-angle spinning (MAS) NMR spectra to be 300 Hz. It is shown that this information is also directly available by 63/65Cu triple-quantum (3Q) MAS NMR. The relative merits of these three approaches to characterizing spin-spin couplings involving half-integer quadrupolar nuclei are discussed. Chemical shielding tensors for nitrogen-15 and carbon-13 are obtained from NMR spectra of non-spinning samples, and are compared to those of tetrahedral group 12 tetracyanometallates. Finally, 2J(63/65Cu,15N) detected in 15N MAS experiments are found to be 19 and 20 Hz for the two crystallographically distinct cyanide ligands.Key words: NMR, quadrupolar nucleus, chemical shielding tensor, multiple-quantum magic-angle spinning, metal cyanide, spin-spin coupling.

Exploiting the Chemical Shielding Anisotropy to Probe Structure and Disorder in Ceramics: 89Y MAS NMR and First-Principles Calculations

2012 ◽  
Vol 116 (6) ◽  
pp. 4273-4286 ◽  
Author(s):  
Martin R. Mitchell ◽  
Diego Carnevale ◽  
Robin Orr ◽  
Karl R. Whittle ◽  
Sharon E. Ashbrook
Keyword(s):  
First Principles ◽  
Mas Nmr ◽  
First Principles Calculations ◽  
Chemical Shielding

Glass Network Evolution with Bi3+/Ti4+Substitution in Phosphate Glasses Formulated with a Constant Oxygen/Phosphorus Ratio. EXAFS, XANES, and31P Double Quantum MAS NMR

2003 ◽  
Vol 15 (25) ◽  
pp. 4709-4716 ◽  
Author(s):  
Lionel Montagne ◽  
Sylvie Daviero ◽  
Gérard Palavit ◽  
Abdelillah Shaim ◽  
Mohamed Et-Tabirou
Keyword(s):  
Glass Network ◽  
Network Evolution ◽  
Phosphate Glasses ◽  
Mas Nmr ◽  
Double Quantum
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