Characterization of Organically Modified Silicates by 17O Solid State MAS and MQ-MAS NMR

1999 ◽  
Vol 576 ◽  
Author(s):  
V. Gualandris ◽  
J. Maquet ◽  
F. Babonneau ◽  
P. Florian ◽  
D. Massiot
Keyword(s):  
Quantitative Analysis ◽  
Solid State ◽  
Magnetic Fields ◽  
Nmr Spectra ◽  
Mas Nmr ◽  
Molar Ratios ◽  
Condensation Reactions ◽  
Organically Modified Silicates ◽  
Organically Modified

ABSTRACTOrganically modified silicates have been prepared, using methyltriethoxysilane and tetraethoxysilane in various molar ratios. The final network is thus composed of trifunctionnal T units and tetrafunctionnal Q units. Three types of oxo bridges can be formed through the competitive self-condensation or co-condensation reactions : (T)-O-(T), (Q)-O-(Q) and (T)-O-(Q). 17O-enriched water was used as reactant in order to selectively enrich the various oxo bridges, and to perform 17O solid state MAS-NMR. The combination of MAS experiments recorded at two different magnetic fields, and of the recently discovered MQ-MAS experiments allowed us to identify clearly the three types of oxo bridges. Quantitative analysis was extracted from the MAS-NMR spectra, and compared with calculations based on randomly distributed Si units.

Solid-State 29Si VACP/MAS NMR Studies of Silicon-Accumulating Plants: Structural Characterization of Biosilica Deposits

2000 ◽  
Vol 55 (6) ◽  
pp. 459-461 ◽  
Author(s):  
Rüdiger Bertermann ◽  
Reinhold Tacke
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Nmr Spectra ◽  
Mas Nmr ◽  
Typical Pattern ◽  
Nmr Studies ◽  
Polysilicic Acid ◽  
Freeze Dried ◽  
Pattern Characteristic

A series of silicon-accumulating plants [different Equisetum (horse tail) species, Echium vulgare, and Symphytum officinale] were studied by solid-state 29Si NMR experiments. For this purpose, selected parts of these plants were freeze-dried and then investigated by solid-state 29Si VACP/MAS NMR spectroscopy. The 29Si NMR spectra of these plants are quite similar and exhibit the typical pattern characteristic of polysilicic acid (amorphous silica).

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

Multinuclear Paramagnetic NMR Spectra and Solid State X-ray Crystallographic Characterization of Manganese(III) Schiff-Base Complexes

1997 ◽  
Vol 36 (22) ◽  
pp. 4968-4982 ◽  
Author(s):  
Yangzhen Ciringh ◽  
Scott W. Gordon-Wylie ◽  
Richard E. Norman ◽  
George R. Clark ◽  
Susan T. Weintraub ◽  
...  
Keyword(s):  
Schiff Base ◽  
Solid State ◽  
Nmr Spectra ◽  
Schiff Base Complexes ◽  
Paramagnetic Nmr ◽  
X Ray

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

Better Characterization of Surface Organometallic Catalysts through Resolution Enhancement in Proton Solid State NMR Spectra

2006 ◽  
Vol 45 (23) ◽  
pp. 9587-9592 ◽  
Author(s):  
Frédéric Blanc ◽  
Christophe Copéret ◽  
Jean Thivolle-Cazat ◽  
Jean-Marie Basset ◽  
Anne Lesage ◽  
...  
Keyword(s):  
Solid State ◽  
Solid State Nmr ◽  
Nmr Spectra ◽  
Resolution Enhancement ◽  
Organometallic Catalysts
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