scholarly journals Paramagnetic 14N MAS NMR without Paramagnetic Shifts: Remarkable Lattice of LaTiO2N and CeTiO2N Oxynitride Perovskites

2020 ◽  
Author(s):  
Zili Ma ◽  
Richard Dronskowski ◽  
Adam Slabon ◽  
Aleksander Jaworski
Keyword(s):  
Solid Material ◽  
Magic Angle Spinning ◽  
Mas Nmr ◽  
Magic Angle ◽  
Molecular Orbital Calculations ◽  
Nmr Spectrum ◽  
H Nmr ◽  
Contact Shift ◽  
Angle Spinning ◽  
Paramagnetic Shifts

<sup>14</sup>N magic-angle spinning (MAS) NMR spectra of diamagnetic LaTiO<sub>2</sub>N perovskite oxynitride and its paramag-<br>netic counterpart CeTiO<sub>2</sub>N are presented. The latter, to the<br>best of our knowledge, constitutes the first high-resolution <sup>14</sup>N MAS NMR spectrum collected from paramagnetic solid material. Induced paramagnetic <sup>14</sup>N NMR shift due to unpaired 4<i>f</i> -electrons in CeTiO<sub>2</sub>N is non-existent, which is remarkable given the severe paramagnetic effects on surface proton species revealed by <sup>1</sup>H NMR, and direct Ce−N contacts in the structure. <i>Ab initio</i> molecular orbital calculations predict substantial Ce→<sup>14</sup>N contact shift interaction under these circumstances, therefore, cannot explain the unprecedented <sup>14</sup>N NMR spectrum of CeTiO<sub>2</sub>N.

scholarly journals Paramagnetic 14N MAS NMR without Paramagnetic Shifts: Remarkable Lattice of LaTiO2N and CeTiO2N Oxynitride Perovskites

2020 ◽  
Author(s):  
Zili Ma ◽  
Richard Dronskowski ◽  
Adam Slabon ◽  
Aleksander Jaworski
Keyword(s):  
Solid Material ◽  
Magic Angle Spinning ◽  
Mas Nmr ◽  
Magic Angle ◽  
Molecular Orbital Calculations ◽  
Nmr Spectrum ◽  
H Nmr ◽  
Contact Shift ◽  
Angle Spinning ◽  
Paramagnetic Shifts

<sup>14</sup>N magic-angle spinning (MAS) NMR spectra of diamagnetic LaTiO<sub>2</sub>N perovskite oxynitride and its paramag-<br>netic counterpart CeTiO<sub>2</sub>N are presented. The latter, to the<br>best of our knowledge, constitutes the first high-resolution <sup>14</sup>N MAS NMR spectrum collected from paramagnetic solid material. Induced paramagnetic <sup>14</sup>N NMR shift due to unpaired 4<i>f</i> -electrons in CeTiO<sub>2</sub>N is non-existent, which is remarkable given the severe paramagnetic effects on surface proton species revealed by <sup>1</sup>H NMR, and direct Ce−N contacts in the structure. <i>Ab initio</i> molecular orbital calculations predict substantial Ce→<sup>14</sup>N contact shift interaction under these circumstances, therefore, cannot explain the unprecedented <sup>14</sup>N NMR spectrum of CeTiO<sub>2</sub>N.

scholarly journals CeTiO2N oxynitride perovskite: paramagnetic 14N MAS NMR without paramagnetic shifts

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Zili Ma ◽  
Can Lu ◽  
Jianhong Chen ◽  
Anna Rokicińska ◽  
Piotr Kuśtrowski ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Nmr Spectra ◽  
Solid Material ◽  
Magic Angle Spinning ◽  
Mas Nmr ◽  
Magic Angle ◽  
Nmr Spectrum ◽  
Contact Shift ◽  
Angle Spinning ◽  
Paramagnetic Shifts

Abstract 14N magic-angle spinning (MAS) nuclear magnetic resonance (NMR) spectra of diamagnetic LaTiO2N perovskite oxynitride and its paramagnetic counterpart CeTiO2N are presented. The latter, to the best of our knowledge, constitutes the first high-resolution 14N MAS NMR spectrum collected from a paramagnetic solid material. The unpaired 4f-electrons in CeTiO2N do not induce a paramagnetic 14N NMR shift. This is remarkable given the direct Ce−N contacts in the structure for which ab initio calculations predict substantial Ce→14N contact shift interaction. The same effect is revealed with 14N MAS NMR for SrWO2N (unpaired 5d-electrons).

scholarly journals Synthesis and structural characterization of neutral hexacoordinate silicon(IV) complexes containing salophen and thiocyanato-N ligands

2018 ◽  
Vol 41 (5-6) ◽  
pp. 135-141
Author(s):  
Gerardo González-García ◽  
Astrid Pérez ◽  
Jorge A. López ◽  
Esneyder Puello-Polo ◽  
Andrés González-García
Keyword(s):  
Solid State ◽  
Magic Angle Spinning ◽  
Mas Nmr ◽  
Magic Angle ◽  
H Nmr ◽  
Elemental Analyses ◽  
Molar Equivalent ◽  
Angle Spinning ◽  
Cp Mas Nmr

Abstract The reaction of the H2salophen ligand, 2,2′-((1E,1′E)-(1,2-phenylenebis(azanylylidene))bis (methanylylidene))diphenol, with one molar equivalent of Si(NCS)4, MeSi(NCS)3 (13), or HMeSi(NCS)2 afforded neutral hexacoordinate silicon complexes, which have an-NCS bi-functionality (complex 1) and mono-functionality (complex 14). The reaction of Si(NCS)4 with the H2salophen-type ligand1,1′-((1E,1′E)-(1,2-phenylenebis(azanylylidene))bis(methanylylidene)) bis(naphthalen-2-ol) (H2Noph), afforded the hexacoordinate silicon complex 15, which has an-NCS bi-functionality. Single-crystal X-ray structural and elemental analyses were used to characterize and confirm the structure of the starting material 13 and complexes 1, 14, and 15. The complexes were characterized in solution by 1H, 13C, and silicon-29 nuclear magnetic resonance (29Si NMR) and in the solid state by 29Si cross-polarization/magic angle spinning (CP/MAS) NMR. Because of the poor solubility of complex 1, it was only possible to characterize it in the solid state by 13C and 29Si CP/MAS NMR and in solution by 1H NMR.

scholarly journals Combination of solid state NMR and DFT calculation to elucidate the state of sodium in hard carbon electrodes

2016 ◽  
Vol 4 (34) ◽  
pp. 13183-13193 ◽  
Author(s):  
Ryohei Morita ◽  
Kazuma Gotoh ◽  
Mika Fukunishi ◽  
Kei Kubota ◽  
Shinichi Komaba ◽  
...  
Keyword(s):  
Solid State ◽  
Solid State Nmr ◽  
Dft Calculation ◽  
Magic Angle Spinning ◽  
The State ◽  
Mas Nmr ◽  
Magic Angle ◽  
Multiple Quantum ◽  
Hard Carbon ◽  
Angle Spinning

We examined the state of sodium electrochemically inserted in HC prepared at 700–2000 °C using solid state Na magic angle spinning (MAS) NMR and multiple quantum (MQ) MAS NMR.

scholarly journals Sampling Method Affects HR-MAS NMR Spectra of Healthy Caprine Brain Biopsies

Metabolites ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 38
Author(s):  
Annakatrin Häni ◽  
Gaëlle Diserens ◽  
Anna Oevermann ◽  
Peter Vermathen ◽  
Christina Precht
Keyword(s):  
Nmr Spectroscopy ◽  
Sampling Method ◽  
Magic Angle Spinning ◽  
Mas Nmr ◽  
Magic Angle ◽  
1H Nuclear Magnetic Resonance ◽  
Rapid Changes ◽  
Tissue Degradation ◽  
Angle Spinning

The metabolic profiling of tissue biopsies using high-resolution–magic angle spinning (HR-MAS) 1H nuclear magnetic resonance (NMR) spectroscopy may be influenced by experimental factors such as the sampling method. Therefore, we compared the effects of two different sampling methods on the metabolome of brain tissue obtained from the brainstem and thalamus of healthy goats by 1H HR-MAS NMR spectroscopy—in vivo-harvested biopsy by a minimally invasive stereotactic approach compared with postmortem-harvested sample by dissection with a scalpel. Lactate and creatine were elevated, and choline-containing compounds were altered in the postmortem compared to the in vivo-harvested samples, demonstrating rapid changes most likely due to sample ischemia. In addition, in the brainstem samples acetate and inositols, and in the thalamus samples ƴ-aminobutyric acid, were relatively increased postmortem, demonstrating regional differences in tissue degradation. In conclusion, in vivo-harvested brain biopsies show different metabolic alterations compared to postmortem-harvested samples, reflecting less tissue degradation. Sampling method and brain region should be taken into account in the analysis of metabolic profiles. To be as close as possible to the actual situation in the living individual, it is desirable to use brain samples obtained by stereotactic biopsy whenever possible.

Metabolic profile of intact tissue from uterine leiomyomas using high-resolution magic-angle-spinning 1 H NMR spectroscopy

2010 ◽  
Vol 23 (10) ◽  
pp. 1137-1145 ◽  
Author(s):  
Pierluigi Mazzei ◽  
Alessandro Piccolo ◽  
Loredana Nugnes ◽  
Massimo Mascolo ◽  
Gaetano De Rosa ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
High Resolution ◽  
Metabolic Profile ◽  
Magic Angle Spinning ◽  
Uterine Leiomyomas ◽  
Magic Angle ◽  
Intact Tissue ◽  
H Nmr ◽  
Angle Spinning

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.

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