Spinning-Frequency-Dependent 31P MAS NMR Spectra of Square-Planar Metal-Phosphine Complexes

1994 ◽  
Vol 33 (13) ◽  
pp. 2774-2778 ◽  
Author(s):  
Gang Wu ◽  
Roderick E. Wasylishen
Keyword(s):  
Nmr Spectra ◽  
Mas Nmr ◽  
Frequency Dependent ◽  
Phosphine Complexes ◽  
Square Planar ◽  
31P Mas Nmr

29Si and 31P MAS-NMR Spectra of Li2S-SiS2-Li3PO4 Rapidly Quenched Glasses

1996 ◽  
Vol 79 (2) ◽  
pp. 349-352 ◽  
Author(s):  
Koichi Hirai ◽  
Masahiro Tatsumisago ◽  
Masanari Takahashi ◽  
Tsutomu Minami
Keyword(s):  
Nmr Spectra ◽  
Mas Nmr ◽  
31P Mas Nmr

Study of Lithium-Lead Phosphate and Borophosphate Glasses

2008 ◽  
Vol 39-40 ◽  
pp. 181-184 ◽  
Author(s):  
Petr Mošner ◽  
Ladislav Koudelka ◽  
Josef Jirák ◽  
Miroslav Vlček
Keyword(s):  
Nmr Spectra ◽  
Glass Structure ◽  
Chemical Durability ◽  
Mas Nmr ◽  
Lead Phosphate ◽  
Borophosphate Glasses ◽  
Structural Network ◽  
31P Mas Nmr ◽  
Glass Series ◽  
Compositional Series

Lithium-lead phosphate and borophosphate glasses were studied in compositional series of xLi2O-(50-x)PbO-50P2O5, xLi2O-(50-x)PbO-10B2O3-40P2O5 and xLi2O-(50-x)PbO-20B2O3- 30P2O5. All glasses crystallize on heating within the range of 400-610oC. Their glass transition temperature decreases with increasing Li2O content in the region of x = 0-30 mol% Li2O and then slowly increases in all series of glasses reflecting thus changes in the bond strength of the glass structural network. Density, molar volume and chemical durability of the glasses decrease with increasing Li2O content. The 31P MAS NMR and Raman spectra show that at all glass series with the replacement of PbO by Li2O the ratio of Q2/Q1 units, present in the structure, slightly increase. The 11B MAS NMR spectra of glasses with 10 mol% B2O3 reveal the presence of only BO4 units in the glass structure, whereas the spectra of the glasses with 20 mol% B2O3 reveal also the presence of small amount of BO3 units.

Solid State MAS-NMR and FTIR Study of Barium Containing Alumino-Silicate Glasses

2007 ◽  
Vol 361-363 ◽  
pp. 825-828 ◽  
Author(s):  
Fei Wang ◽  
Artemis Stamboulis ◽  
D. Holland ◽  
Shigeki Matsuya ◽  
Akari Takeuchi
Keyword(s):  
Nmr Spectra ◽  
Magic Angle Spinning ◽  
Mas Nmr ◽  
Silicate Glasses ◽  
Magic Angle ◽  
Ftir Study ◽  
Alumino Silicate ◽  
31P Mas Nmr ◽  
Angle Spinning ◽  
Second Peak

The glass based on a 1.5SiO2-Al2O3-0.5P2O5-CaO-0.67CaF2 composition was produced and substituted gradually by barium. The structure of the glasses was studied by multinuclear Magic Angle Spinning Nuclear Magnetic Resonance (MAS-NMR) and Fourier Transform Infrared Spectroscopy (FTIR). It was indicated by 29Si and 31P MAS-NMR spectra that silicon was present as Q4 (4Al) and Q3 (3Al) species and phosphorus was in a Q1 pyrophosphate environment. 29Al MAS-NMR spectra showed that four fold coordinated aluminum Al (IV) was the dominant species with a second peak assigned to octahedral aluminum Al (VI). The 19F spectra suggested that the barium addition caused the formation of Al-F-Ba(n) and F-Ba(n) species. Furthermore, a distribution of silicate network including Si-O-Si stretching (Q4 and Q3) and Si-O-[NBO] (Q3) per SiO4 was reflected by the FTIR study.

Investigation of Phosphorus Site Condensation in CaHPO4 by Analysis of 31P MAS-NMR Tensor and X-Ray Powder Patterns

2006 ◽  
Vol 61 (7-8) ◽  
pp. 375-382 ◽  
Author(s):  
Faouzi Hlel ◽  
Saber Kamoun ◽  
Kamel Guidara
Keyword(s):  
Nmr Spectroscopy ◽  
Nmr Spectra ◽  
Room Temperature ◽  
Chemical Shifts ◽  
Mas Nmr ◽  
Slow Evaporation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Annealing Temperatures ◽  
31P Mas Nmr

CaHPO4 was obtained by slow evaporation at room temperature. Seven samples, obtained at different annealing temperatures, were characterized by X-ray diffraction and 31P MAS-NMR spectroscopy. All NMR spectra were analyzed using a DMFIT program. At room temperature, the observed 31P NMR chemical shifts for the title compound were −1.59, −0.36 and 1.26 ppm with the relative intensities 39%, 10% and 51%, revealing the presence of three non-equivalent phosphorus sites in the structure. The investigation of the NMR tensor shift of all spectra shows that the abounding HPO2−4 anion was progressively transformed into P2O4−7 when the temperature increased

scholarly journals Sensitivity gains, linearity, and spectral reproducibility in nonuniformly sampled multidimensional MAS NMR spectra of high dynamic range

2014 ◽  
Vol 59 (2) ◽  
pp. 57-73 ◽  
Author(s):  
Christopher L. Suiter ◽  
Sivakumar Paramasivam ◽  
Guangjin Hou ◽  
Shangjin Sun ◽  
David Rice ◽  
...  
Keyword(s):  
Nmr Spectra ◽  
Dynamic Range ◽  
High Dynamic Range ◽  
Mas Nmr ◽  
High Dynamic

Hydration effects in the carbon-13 CP/MAS NMR spectra of solid (1 →3)-β-D-glucans

1984 ◽  
Vol 17 (3) ◽  
pp. 501-502 ◽  
Author(s):  
C. A. Fyfe ◽  
P. J. Stephenson ◽  
M. G. Taylor ◽  
T. L. Bluhm ◽  
Y. Deslandes ◽  
...  
Keyword(s):  
Nmr Spectra ◽  
Mas Nmr ◽  
Cp Mas Nmr

scholarly journals Shared and unique metabolic features of the malignant and benign thyroid lesions determined with use of 1H HR MAS NMR spectroscopy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Agnieszka Skorupa ◽  
Mateusz Ciszek ◽  
Ewa Chmielik ◽  
Łukasz Boguszewicz ◽  
Małgorzata Oczko-Wojciechowska ◽  
...  
Keyword(s):  
Nmr Spectra ◽  
Univariate Analysis ◽  
Mas Nmr ◽  
Metabolic Reprogramming ◽  
Benign Lesions ◽  
Chronic Thyroiditis ◽  
Malignant Lesions ◽  
Metabolic Heterogeneity ◽  
Benign Thyroid ◽  
Thyroid Lesions

AbstractThe purpose of this work was to investigate the distinct and common metabolic features of the malignant and benign thyroid lesions in reference to the non-transformed tissue from the contralateral gland (chronic thyroiditis and colloid goiter). 1H HR MAS NMR spectra of 38 malignant lesions, 32 benign lesions and 112 samples from the non-tumoral tissue (32 from chronic thyroiditis and 80 samples from colloid goiter) were subjected both to multivariate and univariate analysis. The increased succinate, glutamine, glutathione, serine/cysteine, ascorbate, lactate, taurine, threonine, glycine, phosphocholine/glycerophosphocholine and decreased lipids were found in both lesion types in comparison to either colloid goiter or chronic thyroiditis. The elevated glutamate and choline, and reduced citrate and glucose were additionally evident in these lesions in reference to goiter, while the increased myo-inositol—in comparison to thyroiditis. The malignant lesions were characterized by the higher alanine and lysine levels than colloid goiter and thyroiditis, while scyllo-inositol was uniquely increased in the benign lesions (not in cancer) in comparison to both non-tumoral tissue types. Moreover, the benign lesions presented with the unique increase of choline in reference to thyroiditis (not observed in the cancerous tissue). The metabolic heterogeneity of the non-tumoral tissue should be considered in the analysis of metabolic reprogramming in the thyroid lesions.

Structural Characterization of Glass from the Inversion of23Na and27Al 3Q-MAS NMR Spectra

1999 ◽  
Vol 103 (47) ◽  
pp. 10356-10364 ◽  
Author(s):  
F. Angeli ◽  
T. Charpentier ◽  
P. Faucon ◽  
J.-C. Petit
Keyword(s):  
Structural Characterization ◽  
Nmr Spectra ◽  
Mas Nmr
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