Constancy of the quadrupolar interaction product in nanocrystalline gallium nitride revealed by 71Ga MAS NMR shift distribution

2019 ◽  
Vol 97 ◽  
pp. 25-30 ◽  
Author(s):  
Masataka Tansho ◽  
Takayuki Suehiro ◽  
Tadashi Shimizu
Keyword(s):  
Gallium Nitride ◽  
Mas Nmr ◽  
Quadrupolar Interaction ◽  
Interaction Product

23Na 2D 3QMAS NMR and 29Si, 27Al MAS NMR investigation of Laponite and synthetic saponites of variable interlayer charge

Clay Minerals ◽  
2003 ◽  
Vol 38 (1) ◽  
pp. 63-69 ◽  
Author(s):  
L. Delevoye ◽  
J . -L. Robert ◽  
J . Grandjean
Keyword(s):  
High Resolution ◽  
Chemical Shift ◽  
Chemical Analysis ◽  
Nmr Spectra ◽  
Mas Nmr ◽  
High Resolution Spectrum ◽  
Isotropic Chemical Shift ◽  
Quadrupolar Interaction ◽  
27Al Mas Nmr ◽  
Good Agreement

Abstract29Si, 27Al MAS NMR is used to characterize Laponite RD and synthetic saponites of variable interlayer charge. The Si/Al ratios are in good agreement with the calculated charge from chemical analysis except for the lowest-charged saponite. In contrast to the 29Si MAS NMR spectra in which resolved signals are detected, the 27Al MAS NMR spectra show one signal whose linewidth increases with the clay charge. The water content of the clay samples was obtained from 1H MAS NMR.The 2D MQMAS NMR technique is required to obtain a high-resolution spectrum of nuclei with strong quadrupolar interaction. This method was applied to the 23Na nucleus of clay counterions and to the 27Al structural nucleus. One well-defined 23Na NMR signal is observed for all the clays studied except the highest-charged saponite. Possible explanations for this different behaviour are discussed. The calculated isotropic chemical shift evolves progressively with the clay charge whereas the deduced quadrupolar interaction does not change significantly. The 27Al 2D 3QMAS technique was not able to resolve more than one signal.

Sc2(MoO4)3 and Sc2(WO4)3: Halide Flux Growth of Single Crystals and 45Sc Solid-state NMR

2010 ◽  
Vol 65 (1) ◽  
pp. 13-17 ◽  
Author(s):  
Sarkarainadar Balamurugan ◽  
Ute Ch. Rodewald ◽  
Thomas Harmening ◽  
Leo van Wüllen ◽  
Daniel Mohr ◽  
...  
Keyword(s):  
Single Crystals ◽  
Solid State Nmr ◽  
Nmr Spectra ◽  
Three Dimensional ◽  
Mas Nmr ◽  
Flux Growth ◽  
Quadrupolar Interaction ◽  
X Ray ◽  
Dimensional Network ◽  
Good Agreement

Single crystals of Sc2(TO4)3 with T = Mo and W were synthesized from Sc2O3, MoO3, and WO3 at 1223 K in NaCl / KCl as solvent. Both structures were refined from X-ray diffractometer data: Pbcn, a = 1325.1(1), b = 954.9(1), c = 964.4(1) pm, wR2 = 0.0425, 2097 F2, 79 variables for Sc2(MoO4)3 and a = 1332.9(9), b = 959.4(7), c = 967.9(2) pm, wR2 = 0.0384, 1971 F2, 79 variables for Sc2(WO4)3. The structures consist of a three-dimensional network of corner-sharing ScO6/2 octahedra and two crystallographically independent TO4/2 tetrahedra. 45Sc MAS NMR spectra show sharp single resonances in accordance with the crystallographic data. The quadrupolar interaction parameters obtained from a simulation of the full 45Sc MAS NMR spectra are found to be in good agreement with those obtained from DFT calculations of the electric field gradient

Distributions of Conduction Electrons as Manifested in MAS NMR of Gallium Nitride

2006 ◽  
Vol 128 (15) ◽  
pp. 4952-4953 ◽  
Author(s):  
James P. Yesinowski ◽  
Andrew P. Purdy ◽  
Huaqiang Wu ◽  
Michael G. Spencer ◽  
Janet Hunting ◽  
...  
Keyword(s):  
Gallium Nitride ◽  
Mas Nmr ◽  
Conduction Electrons

A MAS NMR STUDY OF THE STRUCTURE OF AMORPHOUS ALUMINA FILMS

1985 ◽  
Vol 46 (C8) ◽  
pp. C8-113-C8-117 ◽  
Author(s):  
R. Dupree ◽  
I. Farnan ◽  
A. J. Forty ◽  
S. El-Mashri ◽  
L. Bottyan
Keyword(s):  
Mas Nmr ◽  
Alumina Films ◽  
Nmr Study ◽  
Amorphous Alumina

The Role of the Interaction between Fe(III) and Cell Surface in the Accumulation of 67Ga by Tumor Cells

1991 ◽  
Vol 30 (06) ◽  
pp. 290-293 ◽  
Author(s):  
P. Maleki ◽  
A. Martinezi ◽  
M. C. Crone-Escanye ◽  
J. Robert ◽  
L. J. Anghileri
Keyword(s):  
Cell Surface ◽  
Tumor Cells ◽  
Ionic Composition ◽  
Iron Complex ◽  
Iron Binding ◽  
Complex Time ◽  
Interaction Product ◽  
Thermodynamic Constant ◽  
Number Of Cells

The study of the interaction between complexed iron and tumor cells in the presence of 67Ga-citrate indicates that a phenomenon of iron-binding related to the thermodynamic constant of stability of the iron complex, and a hydrolysis (or anion penetration) of the interaction product determine the uptake of 67Ga. The effects of various parameters such as ionic composition of the medium, nature of the iron complex, time of incubation and number of cells are discussed.

Preparation and Properties of Human Prothrombin Complex

1970 ◽  
Vol 24 (03/04) ◽  
pp. 325-333 ◽  
Author(s):  
G. H Tishkoff ◽  
L. C Williams ◽  
D. M Brown
Keyword(s):  
Molecular Weight ◽  
Proteolytic Enzyme ◽  
Enzyme Inhibitor ◽  
Specific Activity ◽  
Crystalline Form ◽  
Sedimentation Equilibrium ◽  
Crystalline Complex ◽  
Interaction Product ◽  
Proteolytic Enzyme Inhibitor ◽  
Purification Scheme

SummaryAs a corollary to our previous studies with bovine prothrombin, we have initiated a study of human prothrombin complex. This product has been isolated in crystalline form as a barium glycoprotein interaction product. Product yields were reduced compared to bovine product due to the increased solubility of the barium glycoprotein interaction product. On occasion the crystalline complex exhibited good yields. The specific activity of the crystalline complex was 1851 Iowa u/mg. Further purification of human prothrombin complex was made by removal of barium and by chromatography on Sephadex G-100 gels. The final product evidenced multiple procoagulant activities (II, VII, IX and X). The monomeric molecular weight determined by sedimentation equilibrium in a solvent of 6 M guanidine-HCl and 0.5% mercaptoethanol was 70,191 ± 3,057 and was homogeneous with respect to molecular weight. This product was characterized in regard to physical constants and chemical composition. In general, the molecular properties of human prothrombin complex are very similar to the comparable bovine product. In some preparations a reversible proteolytic enzyme inhibitor (p-aminophenylarsonic acid) was employed in the ultrafiltration step of the purification scheme to inhibit protein degradation.

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