Yttrium-89 magic angle spinning NMR study of rare-earth pyrochlores: paramagnetic shifts in the solid state

1990 ◽  
Vol 112 (12) ◽  
pp. 4670-4675 ◽  
Author(s):  
Clare P. Grey ◽  
Mark E. Smith ◽  
Anthony K. Cheetham ◽  
Christopher M. Dobson ◽  
Ray Dupree
Keyword(s):  
Rare Earth ◽  
Solid State ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Nmr Study ◽  
Angle Spinning ◽  
Paramagnetic Shifts

Solid-state 17O NMR Study of Small Biological Compounds

2007 ◽  
Vol 62 (11) ◽  
pp. 1422-1432 ◽  
Author(s):  
Kazuhiko Yamada ◽  
Tadashi Shimizu ◽  
Yoshida Mitsuru ◽  
Miwako Asanuma ◽  
Masataka Tansho ◽  
...  
Keyword(s):  
Solid State ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Multiple Quantum ◽  
Peptide Analysis ◽  
17O Nmr ◽  
Nmr Study ◽  
Biological Compounds ◽  
Nmr Tensors ◽  
Angle Spinning

We present a systematic experimental and theoretical investigation of the oxygen chemical shielding and electric-field-gradient tensors in polycrystalline amino acids and a peptide. Analysis of the 17O magic-angle-spinning (MAS), multiple-quantum MAS, and stationary nuclear magnetic resonance (NMR) spectra yield the magnitudes and the relative orientations between the two NMR tensors. The obtained 17O NMR parameters are sensitive to the hydrogen bond environments. We also demonstrate that solid-state 17O NMR is potentially useful for studying the secondary structures of peptides and proteins.

Synthesis, X-ray diffraction and solid-state 31P magic angle spinning NMR study of ?-tricalcium orthophosphate

1996 ◽  
Vol 7 (7) ◽  
pp. 457-463 ◽  
Author(s):  
M. Bohner ◽  
J. LeMa�tre ◽  
A. P. LeGrand ◽  
J.-B. D'Espinose de la Caillerie ◽  
P. Belgrand
Keyword(s):  
Solid State ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nmr Study ◽  
Angle Spinning

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.

scholarly journals 14N, 13C, and 119Sn solid-state NMR characterization of tin(II) carbodiimide Sn(NCN)

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Aleksander Jaworski ◽  
Jędrzej Piątek ◽  
Liuda Mereacre ◽  
Cordula Braun ◽  
Adam Slabon
Keyword(s):  
Solid State ◽  
Solid State Nmr ◽  
Chemical Shifts ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Quadrupolar Coupling ◽  
Nmr Study ◽  
Nmr Characterization ◽  
Angle Spinning ◽  
High Level

Abstract We report the first magic-angle spinning (MAS) nuclear magnetic resonance (NMR) study on Sn(NCN). In this compound the spatially elongated (NCN)2− ion is assumed to develop two distinct forms: either cyanamide (N≡C–N2−) or carbodiimide (−N=C=N−). Our 14N MAS NMR results reveal that in Sn(NCN) the (NCN)2− groups exist exclusively in the form of symmetric carbodiimide ions with two equivalent nitrogen sites, which is in agreement with the X-ray diffraction data. The 14N quadrupolar coupling constant | C Q | $\vert {C}_{\text{Q}}\vert $  ≈ 1.1 MHz for the −N=C=N− ion in Sn(NCN) is low when compared to those observed in molecular compounds that comprise cyano-type N≡C– moieties ( | C Q | $\vert {C}_{\text{Q}}\vert $  > 3.5 MHz). This together with the information from 14N and 13C chemical shifts indicates that solid-state NMR is a powerful tool for providing atomic-level insights into anion species present in these compounds. The experimental NMR results are corroborated by high-level calculations with quantum chemistry methods.

PbO / PbF2 Flux Growth of YScO3 and LaScO3 Single Crystals – Structure and Solid-State NMR Spectroscopy

2010 ◽  
Vol 65 (10) ◽  
pp. 1199-1205 ◽  
Author(s):  
Sarkarainadar Balamurugan ◽  
Ute Ch. Rodewald ◽  
Thomas Harmening ◽  
Leo van Wüllen ◽  
Daniel Mohr ◽  
...  
Keyword(s):  
Rare Earth ◽  
Solid State ◽  
Single Crystals ◽  
Solid State Nmr ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Flux Growth ◽  
Quadrupolar Interaction ◽  
Angle Spinning ◽  
Good Agreement

Well-shaped small single crystals of the orthorhombic perovskites YScO3 and LaScO3 were grown from mixtures of the corresponding sesquioxides RE2O3 in PbO/PbF2 fluxes. Both structures were refined from single-crystal diffractometer data: GdFeO3-type, Pnma, a = 570.68(7), b = 789.3(1), c = 542.44(7) pm, wR2 = 0.0363, 448 F2 values for Y0.96ScO2.94, and a = 579.68(9), b = 810.3(2), c = 568.3(1) pm, wR2 = 0.0387, 513 F2 values for La0.94ScO2.91, with 32 variables per refinement. The 4c rare-earth sites of both perovskites show small defects which are charge-compensated by defects on both oxygen sites, leading to the compositions La0.94ScO2.91 and Y0.96ScO2.94 for the investigated crystals. The rare-earth sites have been characterized by 89Y and 45Sc magic-angle spinning (MAS) NMR. The 45Sc quadrupolar interaction parameters extracted from these spectra by simulations are found to be in good agreement with those obtained from DFT calculations of the electric field gradient.

Solid-state bromination of poly(1,6-di-N-carbazolyl-2,4-hexadiyne): a cross polarization-magic angle spinning NMR study

1987 ◽  
Vol 109 (3) ◽  
pp. 761-768 ◽  
Author(s):  
Hellmut Eckert ◽  
James P. Yesinowski ◽  
Daniel J. Sandman ◽  
Christopher S. Velazquez
Keyword(s):  
Solid State ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Cross Polarization ◽  
Nmr Study ◽  
Angle Spinning

Distribution of water in the pores of periodic mesoporous organosilicates – a proton solid state MAS NMR study

2018 ◽  
Vol 20 (46) ◽  
pp. 29351-29361 ◽  
Author(s):  
V. S. Veena ◽  
Kavya Illath ◽  
Anish Lazar ◽  
C. P. Vinod ◽  
T. G. Ajithkumar ◽  
...  
Keyword(s):  
Solid State ◽  
Nmr Spectra ◽  
Magic Angle Spinning ◽  
Mas Nmr ◽  
Magic Angle ◽  
Pore Filling ◽  
Nmr Study ◽  
Proposed Model ◽  
Water Layers ◽  
Angle Spinning

Proposed model of water layers and pore filling in ethane substituted periodic mesoporous organosilicates (PMOE) based on analysis of solid state magic angle spinning (MAS) proton NMR spectra.

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