scholarly journals On the preparation and NMR spectroscopic characterization of potassium aluminium tetrahydride KAlH4

2019 ◽  
Vol 21 (23) ◽  
pp. 12576-12584 ◽  
Author(s):  
Bodo Zibrowius ◽  
Michael Felderhoff
Keyword(s):  
Nmr Spectroscopy ◽  
Chemical Shift ◽  
Spectroscopic Characterization ◽  
Mas Nmr ◽  
Isotropic Chemical Shift ◽  
Quadrupole Coupling ◽  
Coupling Parameters

Conventional 1D 27Al MAS NMR spectroscopy allows the isotropic chemical shift and the quadrupole coupling parameters of Pnma KAlH4 to be determined precisely.

14N MAS NMR Spectroscopy and Quadrupole Coupling Data in Characterization of the IV ↔ III Phase Transition in Ammonium Nitrate

2002 ◽  
Vol 106 (11) ◽  
pp. 3026-3032 ◽  
Author(s):  
Tania Giavani ◽  
Henrik Bildsøe ◽  
Jørgen Skibsted ◽  
Hans J. Jakobsen
Keyword(s):  
Phase Transition ◽  
Nmr Spectroscopy ◽  
Ammonium Nitrate ◽  
Mas Nmr ◽  
Quadrupole Coupling

Aluminum Siting in the ZSM-22 and Theta-1 Zeolites Revisited: A QM/MM Study

2008 ◽  
Vol 73 (6-7) ◽  
pp. 909-920 ◽  
Author(s):  
Stepan Sklenak ◽  
Jiří Dědeček ◽  
Chengbin Li ◽  
Fei Gao ◽  
Bavornpon Jansang ◽  
...  
Keyword(s):  
Experimental Data ◽  
Chemical Shift ◽  
Nearest Neighbor ◽  
Membered Ring ◽  
Mas Nmr ◽  
Isotropic Chemical Shift ◽  
Reaction Space ◽  
Ring Channel ◽  
T1 And T2 ◽  
Nmr Signals

The Al siting in the silicon rich ZSM-22 and Theta-1 zeolites of the TON structure was investigated analyzing already published 27Al 3Q MAS NMR experimental data using QM/MM calculations. The results of our computations show that Al atoms can be located in 6 framework T positions because the two eightfold sites (T1 and T2) split into four fourfold T sites after an Al/Si substitution. The observed resonance at 55.5 ppm corresponds to the T4 site which is predominantly occupied by Al. This site is not located on the surface of the TON ten-membered ring channel and thus the protonic sites related with the majority of Al atoms in the TON structure exhibit a significantly limited reaction space. The 27Al NMR signals centered at 57.6 and 58.7 ppm correspond to either the T2 and T3 sites, respectively, or only to T2. The T2 and T3 sites accommodate some 40% and up to 10%, respectively, of Al while the T1 site is unoccupied by Al. Isotropic shifts of 61.1 and 61.6 ppm were calculated for Al atoms located in the T1-1 and T1-2 sites, respectively. The effect of a silanol "nest" as a next-next-nearest neighbor on the 27Al isotropic chemical shift of Al located in the T4 site is calculated to be less than 1 ppm.

Structural characterization of ionomer glasses by multinuclear solid state MAS-NMR spectroscopy

2007 ◽  
Vol 353 (3) ◽  
pp. 237-243 ◽  
Author(s):  
Shigeki Matsuya ◽  
Artemis Stamboulis ◽  
Robert G. Hill ◽  
Robert V. Law
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Structural Characterization ◽  
Mas Nmr

Darstellung und spektroskopische Charakterisierung von Methoxysulfoniumsalzen. R2SOCH3+X-(R = F, Cl, CF3, CH3; X- = AsF6-, SbF6-, Sb2F11- )/Preparation and Spectroscopic Characterization of Methoxysulfonium Salts. R2SOCH3+X- (R = F, CI, CF3, CH3; X- = AsF6-, SbF6- , Sb2F11-)

1992 ◽  
Vol 47 (1) ◽  
pp. 22-26 ◽  
Author(s):  
Rolf Minkwitz ◽  
Walter Molsbeck
Keyword(s):  
Nmr Spectroscopy ◽  
Spectroscopic Characterization ◽  
Sulfonium Salts

The preparation of the sulfonium salts R2SOCH3+X- (R = F, Cl, CF3, CH3; X- = AsF6-, SbF6-, Sb2F11-) is reported. The compounds have been obtained from the sulfuranes R2SO with reagents CH3OSO+MF6- (M = As, Sb) in liquid SO2 and characterized by Raman and 1H , 13C, and 19F NMR spectroscopy.

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