Na3GaF6 – A crystal chemical and solid state NMR spectroscopic study

2018 ◽  
Vol 233 (7) ◽  
pp. 479-487 ◽  
Author(s):  
David Böhnisch ◽  
Stefan Seidel ◽  
Christopher Benndorf ◽  
Thomas Jansen ◽  
Lena Funke ◽  
...  
Keyword(s):  
Solid State Nmr ◽  
Nmr Spectra ◽  
Chemical Exchange ◽  
Center Of Mass ◽  
Mas Nmr ◽  
X Ray Diffraction ◽  
X Ray ◽  
Exchange Effects ◽  
Distorted Octahedral ◽  
Motional Narrowing

Abstract Na3GaF6 and Na3GaF6:Mn4+ samples were obtained from NaNO3 and Ga(NO3)3·9H2O in hydrofluoric acid using K2MnF6 or NaMnO4 as manganese sources. The structure of Na3GaF6 was studied by single crystal X-ray diffraction at 90, 293, 440 and 500 K, confirming the monoclinic cryolite type structure, space group P21/c. The gallium atoms show slightly distorted octahedral coordination by fluorine atoms, similar to the Na1 atoms. Coordination number 8 is observed for Na2. Both sodium sites are clearly distinguished by 23Na MAS-NMR spectroscopy. Above 400 K the spectra reveal distinct chemical exchange effects, signifying sodium ion hopping between these two sites. At the same time static 19F NMR spectra indicate pronounced motional narrowing effects in this temperature region. The nearly invariant 69Ga MAS-NMR spectra suggest that any reorientational motion involving the GaF63− ions (if present) occurs with preservation of the center of mass of these octahedra.

Characterization of aluminosilicate (mullite) precursors prepared by a mechanochemical process

1998 ◽  
Vol 13 (8) ◽  
pp. 2184-2189 ◽  
Author(s):  
J. Temuujin ◽  
K. Okada ◽  
K. J. D. MacKenzie
Keyword(s):  
Heat Treatment ◽  
Nmr Spectra ◽  
Spinel Phase ◽  
Mas Nmr ◽  
X Ray Diffraction ◽  
Hydrated Alumina ◽  
X Ray ◽  
New Si ◽  
Grinding Time

Aluminosilicate precursors were prepared by mechanochemical treatment of gibbsitesilica gel mixtures. The effect of grinding on their structure and thermal behavior has been examined by 27Al and 29Si MAS NMR, x-ray diffraction (XRD), differential thermal analysis-thermogravimetry (DTA-TG), and Fourier transform infrared (FTIR). After 8 h grinding, the hydrated alumina was completely changed to an amorphous phase which showed a new exothermic DTA peak at about 980 °C due to the formation of γ–Al2O3 or spinel phase. This behavior was related to changes in the Al and Si environments, as deduced from the MAS NMR spectra. With increased grinding time, some 4-coordinated Al appears, together with an Al resonance at about 30 ppm. Simultaneously, a new Si resonance appears at about −90 ppm, indicating a greater degree of homogeneity in the ground samples. Mullite crystallizes at 1200 °C from samples ground for 8–20 h, its XRD intensity increasing with increased milling times, in agreement with the NMR, DTA, and FTIR data. Changes in the Al and Si environments during heat treatment, as reflected by the NMR spectra, are also reported.

Multinuclear NMR and Powder X-ray Diffraction Studies of Si and Sn Clathrates of Alkali Metals: Vacancies, Disorder and Knight Shifts

2001 ◽  
Vol 691 ◽  
Author(s):  
Michael J. Ferguson ◽  
Igor L. Moudrakovski ◽  
Christopher I. Ratcliffe ◽  
John S. Tse
Keyword(s):  
Solid State ◽  
Solid State Nmr ◽  
Nmr Spectra ◽  
Alkali Metals ◽  
Rietveld Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Multinuclear Nmr ◽  
Binary Metal ◽  
Knight Shifts

ABSTRACTThe Structure I type binary metal clathrates of K/Si, Rb/Si and Cs/Sn have been synthesised and studied by powder X-ray diffraction and solid state NMR. Rietveld analysis shows that in all three materials some of the cages are empty, and that in the Cs/Sn clathrate there are vacancies in the Sn framework. The NMR results yield Knight shifts for 29Si and 39K and confirm that the Cs/Sn clathrate is not conducting. Many of the features of the NMR spectra can be understood in terms of the distributions of atom vacancies.

Tetra(alkynyl)silanes, a 3,6-Disila-triyne, a 3,6,9-Trisila-tetrayne, a 1,3,4,6-Tetrasiladiyne, and Bis(trimethylstannyl)ethyne. Molecular Structures and Solid-state NMR Studies

2010 ◽  
Vol 65 (2) ◽  
pp. 119-127 ◽  
Author(s):  
Bernd Wrackmeyer ◽  
Ezzat Khan ◽  
Amin Badshah ◽  
Elias Molla ◽  
Peter Thoma ◽  
...  
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Solid State Nmr ◽  
Mas Nmr ◽  
Molecular Structures ◽  
X Ray Diffraction ◽  
Nmr Studies ◽  
X Ray ◽  
Solution State ◽  
Nmr Data

The molecular structures of three alkynylsilanes, tetrakis(ethynyl-p-tolyl)silane, 3,3,6,6,-tetramethyl- 3,6-disila-triyne, 3,3,6,6,9,9,-hexamethyl-3,6,9-trisila-tetrayne, and of bis(trimethylstannyl)- ethyne have been determined by X-ray diffraction. The same alkynylsilanes, and in addition 1,2- bis(trimethylsilylethynyl)-1,1,2,2-tetramethyldisliane, were studied by solid-state 13C and 29Si MAS NMR spectroscopy. The results of these measurements were compared with crystallographic evidence and also with relevant solution-state NMR data.

Structural organization of mercury(II) and copper(II) dithiocarbamates from EPR and 13C and 15N MAS NMR spectra and X-ray diffraction analysis

2008 ◽  
Vol 34 (1) ◽  
pp. 59-69 ◽  
Author(s):  
A. V. Ivanov ◽  
E. V. Korneeva ◽  
B. V. Bukvetskii ◽  
A. S. Goryan ◽  
O. N. Antzutkin ◽  
...  
Keyword(s):  
Diffraction Analysis ◽  
Nmr Spectra ◽  
Structural Organization ◽  
Mas Nmr ◽  
X Ray Diffraction ◽  
X Ray

Effect of the cation mobility on the X-ray diffraction pattern and the Si MAS NMR spectra of Na,CoY zeolites

1998 ◽  
Vol 21 (1-3) ◽  
pp. 19-25 ◽  
Author(s):  
M Solache ◽  
I Garcı́a ◽  
P Bosch ◽  
S Bulbulian ◽  
A Blumenfeld ◽  
...  
Keyword(s):  
Diffraction Pattern ◽  
Nmr Spectra ◽  
Mas Nmr ◽  
X Ray Diffraction ◽  
Cation Mobility ◽  
X Ray

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

6Li and 7Li MAS NMR and In Situ X-ray Diffraction Studies of Lithium Manganate Cathode Materials

1998 ◽  
Vol 548 ◽  
Author(s):  
Young Joo Lee ◽  
Francis Wang ◽  
Clare P. Grey ◽  
Sanjeev Mukerjee ◽  
James McBreen
Keyword(s):  
Cathode Materials ◽  
Nmr Spectra ◽  
Manganese Oxides ◽  
Mas Nmr ◽  
X Ray Diffraction ◽  
Two Phase ◽  
X Ray ◽  
Lithium Manganese Oxides ◽  
Diffraction Patterns

ABSTRACT6Li MAS NMR spectra of lithium manganese oxides with differing manganese oxidation states (LiMn2O4, Li4Mn5O12, Li2Mn4O9, and Li2Mn2O4) are presented. Improved understanding of the lithium NMR spectra of these model compounds is used to interpret the local structure of the LixMn2O4 cathode materials following electrochemical Li+ deintercalation to various charging levels. In situ x-ray diffraction patterns of the same material during charging are also reported for comparison. Evidence for two-phase behavior for x < 0.4 (LixMn2O4) is seen by both NMR and diffraction.

scholarly journals Insight into the Crystal Structures and Physical Properties of the Uranium Borides UB1.78±0.02, UB3.61±0.041 and UB11.19±0.13

Minerals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 29
Author(s):  
Laura Martel ◽  
Thibault Charpentier ◽  
Pedro Amador Cedran ◽  
Chris Selfslag ◽  
Mohamed Naji ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Infrared Spectroscopy ◽  
Solid State Nmr ◽  
Nmr Spectra ◽  
Squid Magnetometry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fourier Transformed Infrared Spectroscopy ◽  
5F Electrons ◽  
Insight Into

In this study we reported the synthesis of three polycrystalline uranium borides UB1.78±0.02, UB3.61±0.041, and UB11.19±0.13 and their analyses using chemical analysis, X-ray diffraction, SQUID magnetometry, solid-state NMR, and Fourier transformed infrared spectroscopy. We discuss the effects of stoichiometry deviations on the lattice parameters and magnetic properties. We also provide their static and MAS-NMR spectra showing the effects of the 5f-electrons on the 11B shifts. Finally, the FTIR measurements showed the presence of a local disorder.

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

The Electron Effect of Aromatic Group: Control Conformation of 2-Aromatic Cyclododecanone Derivatives

2020 ◽  
Vol 24 (10) ◽  
pp. 1139-1147
Author(s):  
Yang Mingyan ◽  
Wang Daoquan ◽  
Wang Mingan
Keyword(s):  
1H Nmr ◽  
13C Nmr ◽  
Nmr Spectra ◽  
Coupling Constants ◽  
The Other ◽  
Repulsive Interaction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electron Effect ◽  
Group Control

2-Phenylcyclododecanone and 2-cyclohexylcyclododecanone derivatives were synthesized and characterized by 1H NMR, 13C NMR, HR-ESI-MS and X-ray diffraction. Their preferred conformations were analyzed by the coupling constants in the 1H NMR spectra and X-ray diffraction, which showed the skeleton ring of these derivatives containing [3333]-2-one conformation, and the phenyl groups were located at the side-exo position of [3333]-2-one conformation due to the strong π-π repulsive interaction between the π- electron of benzene ring and π-electron of carbonyl group. The cyclohexyl groups were located at the corner-syn or the side-exo position of [3333]-2-one conformation depending on the hindrance of the other substituted groups. The π-π electron effect played a crucial role in efficiently controlling the preferred conformation of 2-aromatic cyclododecanone and the other 2-aromatic macrocyclic derivatives with the similar preferred square and rectangular conformations.

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