Computational prediction and analysis of the 27Al solid-state NMR spectrum of methylaluminoxane (MAO) at variable temperatures and field strengths

2016 ◽  
Vol 18 (34) ◽  
pp. 24106-24118 ◽  
Author(s):  
Zackary Falls ◽  
Eva Zurek ◽  
Jochen Autschbach
Keyword(s):  
Solid State ◽  
Solid State Nmr ◽  
Computational Prediction ◽  
Mas Nmr ◽  
Nmr Spectrum ◽  
Co Catalyst ◽  
Catalytically Active ◽  
Field Strengths

27Al MAS NMR of the co-catalyst methylaluminoxane may be able to reveal the fraction of species that are catalytically active.

High-resolution solid-state NMR investigation of the nature of the interaction between organic substrates and the zeolite ZSM-5 lattice

1988 ◽  
Vol 66 (8) ◽  
pp. 1942-1947 ◽  
Author(s):  
C. A. Fyfe ◽  
H. Strobl ◽  
H. Gies ◽  
G. T. Kokotailo
Keyword(s):  
Solid State ◽  
High Resolution ◽  
Phase Change ◽  
Solid State Nmr ◽  
Organic Molecules ◽  
Lattice Structure ◽  
Model System ◽  
Mas Nmr ◽  
Organic Substrates ◽  
Nmr Spectrum

The compounds p-xylene, p-chlorotoluene, and p-dichlorobenzene induce essentially identical changes in the 29Si MAS NMR spectrum of zeolite ZSM-5, indicating that the major contribution to the induced phase change of the lattice structure in these cases is the size and shape of the sorbed organic molecules. Based on these results, p-dichlorobenzene may be used as a model system in future diffraction studies of the sorbate/lattice structure greatly facilitating these investigations.

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.

Investigating Sorption on Iron−Oxyhydroxide Soil Minerals by Solid-State NMR Spectroscopy:  A6Li MAS NMR Study of Adsorption and Absorption on Goethite

2005 ◽  
Vol 109 (39) ◽  
pp. 18310-18315 ◽  
Author(s):  
Ulla Gro Nielsen ◽  
Younkee Paik ◽  
Keinia Julmis ◽  
Martin A. A. Schoonen ◽  
Richard J. Reeder ◽  
...  
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Solid State Nmr ◽  
Mas Nmr ◽  
Iron Oxyhydroxide ◽  
Soil Minerals ◽  
Solid State Nmr Spectroscopy ◽  
Nmr Study

scholarly journals 14N1H HMQC Solid-State NMR as a Powerful Tool to Study Amorphous Formulations – an Exemplary Study of Paclitaxel Loaded Polymer Micelles

2020 ◽  
Author(s):  
Marvin Grüne ◽  
Robert Luxenhofer ◽  
Dinu Iuga ◽  
Steven P. Brown ◽  
Ann-Christin Pöppler
Keyword(s):  
Solid State ◽  
Solid State Nmr ◽  
Chemical Shifts ◽  
Mas Nmr ◽  
Cancer Drug ◽  
Polymer Micelles ◽  
Promising Tool ◽  
Nmr Characterization

We present <sup>14</sup>N-<sup>1</sup>H HMQC MAS NMR experiments in the solid state as a promising tool to study amorphous formulations. Poly(2-oxazoline) based polymer micelles loaded with different amounts of the cancer drug paclitaxel serve to highlight the possibilities offered by these experiments: While the very similar <sup>15</sup>N chemical shifts hamper a solid-state NMR characterization based on this nucleus, <sup>14</sup>N is a very versatile alternative. <sup>14</sup>N-<sup>1</sup>H HMQC experiments yield well-separated signals, which are spread over a large ppm range, provide information on the symmetry of the nitrogen environment and probe <sup>14</sup>N-<sup>1</sup>H through-space proximities.

scholarly journals Distinguishing tautomerism in the crystal structure of (Z)-N-(5-ethyl-2,3-dihydro-1,3,4-thiadiazol-2-ylidene)-4-methylbenzenesulfonamide using DFT-D calculations and13C solid-state NMR

2014 ◽  
Vol 70 (8) ◽  
pp. 784-789 ◽  
Author(s):  
Xiaozhou Li ◽  
Andrew D. Bond ◽  
Kristoffer E. Johansson ◽  
Jacco Van de Streek
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Solid State Nmr ◽  
Density Functional ◽  
Acta Cryst ◽  
Protonation Site ◽  
Nmr Spectrum ◽  
Compound C ◽  
Intermolecular Contacts ◽  
Thiadiazole Ring

The crystal structure of the title compound, C11H13N3O2S2, has been determined previously on the basis of refinement against laboratory powder X-ray diffraction (PXRD) data, supported by comparison of measured and calculated13C solid-state NMR spectra [Hanganet al.(2010).Acta Cryst.B66, 615–621]. The molecule is tautomeric, and was reported as an amine tautomer [systematic name:N-(5-ethyl-1,3,4-thiadiazol-2-yl)-p-toluenesulfonamide], rather than the correct imine tautomer. The protonation site on the molecule's 1,3,4-thiadiazole ring is indicated by the intermolecular contacts in the crystal structure: N—H...O hydrogen bonds are established at the correct site, while the alternative protonation site does not establish any notable intermolecular interactions. The two tautomers provide essentially identical Rietveld fits to laboratory PXRD data, and therefore they cannot be directly distinguished in this way. However, the correct tautomer can be distinguished from the incorrect one by previously reported quantitative criteria based on the extent of structural distortion on optimization of the crystal structure using dispersion-corrected density functional theory (DFT-D) calculations. Calculation of the13C SS-NMR spectrum based on the correct imine tautomer also provides considerably better agreement with the measured13C SS-NMR spectrum.

Oxidative coupling of naphtho-9-crown-3 ether: X-ray crystal structure and solution and solid-state NMR analysis of the dimer

2001 ◽  
Vol 79 (10) ◽  
pp. 1505-1510 ◽  
Author(s):  
G W Buchanan ◽  
M F Rastegar ◽  
G PA Yap ◽  
A Moghimi ◽  
M Ghandi
Keyword(s):  
Solid State ◽  
Oxidative Coupling ◽  
Solid State Nmr ◽  
Nmr Analysis ◽  
Oxidative Dimerization ◽  
Nmr Spectrum ◽  
X Ray ◽  
Nmr Data ◽  
Group A ◽  
C Nmr

Treatment of naphtho-9-crown-3 ether with FeCl3 and aqueous H2SO4 generates bis-naphtho-9-crown-3 ether in ca. 30% yield. This compound crystallizes in the monoclinic P21/n space group; a = 9.2004(9), b = 18.0868(17), and c = 13.2078(13) Å, β = 97.799(2)° and Z = 4. 1H and 13C NMR data have been obtained in solution, and the solid-state 13C NMR spectrum is included for comparison. A chemical shift range of ca. 12 ppm has been found for the oxygenated aliphatic carbons in the solid state, in contrast to the 3 ppm range in the solution 13C NMR spectrum. These results are discussed in terms of the torsional environments of the carbon sites in the crystal structure.Key words: crown ether, stereochemistry, oxidative dimerization.

2H-solid-state-NMR study of hydrogen adsorbed on catalytically active ruthenium coated mesoporous silica materials

2009 ◽  
Vol 35 (3) ◽  
pp. 164-171 ◽  
Author(s):  
Bernadeta Walaszek ◽  
Xu Yeping ◽  
Anna Adamczyk ◽  
Hergen Breitzke ◽  
Katrin Pelzer ◽  
...  
Keyword(s):  
Solid State ◽  
Mesoporous Silica ◽  
Solid State Nmr ◽  
Nmr Study ◽  
Silica Materials ◽  
Catalytically Active ◽  
Mesoporous Silica Materials

Grafting trimethylaluminum and its halogen derivatives on silica: general trends for 27Al SS-NMR response from first principles calculations

2015 ◽  
Vol 17 (40) ◽  
pp. 26937-26945 ◽  
Author(s):  
Rachel Nathaniel Kerber ◽  
Torsten Kerber ◽  
Xavier Rozanska ◽  
Françoise Delbecq ◽  
Philippe Sautet
Keyword(s):  
Solid State ◽  
First Principles ◽  
Solid State Nmr ◽  
First Principles Calculations ◽  
Nmr Spectrum ◽  
Halogen Compounds

27Al solid-state NMR spectrum and parameters for various types of Al monomeric and dimeric alkyl and halogen compounds grafted on silica are interpreted based on the trends obtained from first-principles calculations.

scholarly journals A novel multinuclear solid-state NMR approach for the characterization of kidney stones

2021 ◽  
Vol 2 (2) ◽  
pp. 653-671
Author(s):  
César Leroy ◽  
Laure Bonhomme-Coury ◽  
Christel Gervais ◽  
Frederik Tielens ◽  
Florence Babonneau ◽  
...  
Keyword(s):  
Solid State ◽  
Kidney Stones ◽  
Solid State Nmr ◽  
Magic Angle Spinning ◽  
Mas Nmr ◽  
Magic Angle ◽  
Nmr Studies ◽  
Stone Composition ◽  
Analytical Technique ◽  
Nmr Data

Abstract. The spectroscopic study of pathological calcifications (including kidney stones) is extremely rich and helps to improve the understanding of the physical and chemical processes associated with their formation. While Fourier transform infrared (FTIR) imaging and optical/electron microscopies are routine techniques in hospitals, there has been a dearth of solid-state NMR studies introduced into this area of medical research, probably due to the scarcity of this analytical technique in hospital facilities. This work introduces effective multinuclear and multidimensional solid-state NMR methodologies to study the complex chemical and structural properties characterizing kidney stone composition. As a basis for comparison, three hydrates (n=1, 2 and 3) of calcium oxalate are examined along with nine representative kidney stones. The multinuclear magic angle spinning (MAS) NMR approach adopted investigates the 1H, 13C, 31P and 31P nuclei, with the 1H and 13C MAS NMR data able to be readily deconvoluted into the constituent elements associated with the different oxalates and organics present. For the first time, the full interpretation of highly resolved 1H NMR spectra is presented for the three hydrates, based on the structure and local dynamics. The corresponding 31P MAS NMR data indicates the presence of low-level inorganic phosphate species; however, the complexity of these data make the precise identification of the phases difficult to assign. This work provides physicians, urologists and nephrologists with additional avenues of spectroscopic investigation to interrogate this complex medical dilemma that requires real, multitechnique approaches to generate effective outcomes.

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