The phosphorus-31 chemical shielding tensor in phospholipids

1988 ◽  
Vol 110 (4) ◽  
pp. 1054-1058 ◽  
Author(s):  
H. Hauser ◽  
C. Radloff ◽  
Richard R. Ernst ◽  
S. Sundell ◽  
I. Pascher
1987 ◽  
Vol 86 (10) ◽  
pp. 5405-5410 ◽  
Author(s):  
Marie‐Rose Van Calsteren ◽  
George I. Birnbaum ◽  
Ian C. P. Smith

2004 ◽  
Vol 6 (10) ◽  
pp. 1097-1105 ◽  
Author(s):  
M. Bechmann ◽  
S. Dusold ◽  
A. Sebald ◽  
W.A. Shuttleworth ◽  
D.L. Jakeman ◽  
...  

1999 ◽  
Vol 77 (11) ◽  
pp. 1962-1972
Author(s):  
Scott Kroeker ◽  
Roderick E Wasylishen

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.


2006 ◽  
Vol 110 (29) ◽  
pp. 9137-9144 ◽  
Author(s):  
Carole Gardiennet-Doucet ◽  
Xavier Assfeld ◽  
Bernard Henry ◽  
Piotr Tekely

1981 ◽  
Vol 74 (6) ◽  
pp. 3190-3197 ◽  
Author(s):  
A. Naito ◽  
S. Ganapathy ◽  
K. Akasaka ◽  
C. A. McDowell

1989 ◽  
Vol 67 (3) ◽  
pp. 454-459 ◽  
Author(s):  
William P. Power ◽  
Roderick E. Wasylishen ◽  
Ronald D. Curtis

Simultaneous observation of anisotropic chemical shielding and dipolar coupling in polycrystalline monophosphazenes has been used to obtain information on the 31P–14N spin pair. Phosphorus-31 chemical shielding tensor components have been determined; the most shielded component was found to lie along the P=N bond. The 31P–14N dipolar coupling constants have provided P=N bond lengths from powder samples, equivalent for all compounds within experimental error; the value obtained for N–(triphenylphosphoranylidene)-aniline is in excellent agreement with that obtained in a recent X-ray diffraction study. Features of crystallographic significance have been determined from the solid-state nuclear magnetic resonance spectra for two of the compounds without resorting to diffraction techniques. Information on the magnitude and orientation of the 14N electric field gradient tensor has been inferred from 31P MAS spectra and abinitio calculations. Keywords: monophosphazenes, dipolar nmr, 31P chemical shielding anisotropies, solid-state nmr.


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