Do Alkali Metal Anions (M−) Exist in Zeolite A?

1996 ◽  
Vol 431 ◽  
Author(s):  
P. D. Barker ◽  
P. A. Anderson ◽  
R. Dupree ◽  
S. Kitchin ◽  
P. P. Edwards ◽  
...  
Keyword(s):  
Solid State ◽  
Neutron Diffraction ◽  
Alkali Metal ◽  
Mas Nmr ◽  
Zeolite A ◽  
Nmr Studies ◽  
Mixed Metal ◽  
Powder Neutron Diffraction ◽  
Wide Range ◽  
Sodium And Potassium

AbstractRecent NMR studies by Nakayama et al. on sodium zeolite A saturated with potassium metal have implied the presence of the anionic Na− species. This, if confirmed, would represent the first observation in a zeolite and opens up a wide range of possibilities for mixed metal zeolitic systems. We report the results of a number of metal combinations, using both sodium and potassium forms of zeolite A as hosts, studied by ESR, solid state MAS-NMR and powder neutron diffraction.

Powder Neutron Diffraction and 29Si MAS NMR Studies of Siliceous Zeolite-Y

1993 ◽  
Vol 106 (1) ◽  
pp. 66-72 ◽  
Author(s):  
J.A. Hriljac ◽  
M.M. Eddy ◽  
A.K. Cheetham ◽  
J.A. Donohue ◽  
G.J. Ray
Keyword(s):  
Neutron Diffraction ◽  
Zeolite Y ◽  
Mas Nmr ◽  
29Si Mas Nmr ◽  
Nmr Studies ◽  
Powder Neutron Diffraction

Neutron diffraction and solid-state MAS-NMR studies of the structure of Y-AI-Si-O-N oxynitride glasses

1994 ◽  
Vol 70 (2) ◽  
pp. 191-203 ◽  
Author(s):  
Jisun Jin ◽  
Toshinobu Yoko ◽  
Fumiaki Miyaji ◽  
Sumio Sakka ◽  
Toshiharu Fukunaga ◽  
...  
Keyword(s):  
Solid State ◽  
Neutron Diffraction ◽  
Mas Nmr ◽  
Nmr Studies

The Nature of Chemisorbed CO2 in Zeolite A

2019 ◽  
Author(s):  
Przemyslaw Rzepka ◽  
Zoltán Bacsik ◽  
Andrew J. Pell ◽  
Niklas Hedin ◽  
Aleksander Jaworski
Keyword(s):  
Solid State ◽  
Ir Spectroscopy ◽  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Surface Coverage ◽  
Gas Mixtures ◽  
Mas Nmr ◽  
Significant Fraction ◽  
Zeolite A

Formation of CO<sub>3</sub><sup>2-</sup> and HCO<sub>3</sub><sup>-</sup> species without participation of the framework oxygen atoms upon chemisorption of CO<sub>2</sub> in zeolite |Na<sub>12</sub>|-A is revealed. The transfer of O and H atoms is very likely to have proceeded via the involvement of residual H<sub>2</sub>O or acid groups. A combined study by solid-state <sup>13</sup>C MAS NMR, quantum chemical calculations, and <i>in situ</i> IR spectroscopy showed that the chemisorption mainly occurred by the formation of HCO<sub>3</sub><sup>-</sup>. However, at a low surface coverage of physisorbed and acidic CO<sub>2</sub>, a significant fraction of the HCO<sub>3</sub><sup>-</sup> was deprotonated and transformed into CO<sub>3</sub><sup>2-</sup>. We expect that similar chemisorption of CO<sub>2</sub> would occur for low-silica zeolites and other basic silicates of interest for the capture of CO<sub>2</sub> from gas mixtures.

Solid-State MAS NMR Studies of Sulfonic Acid-Functionalized SBA-15

2007 ◽  
Vol 32 (4) ◽  
pp. 513-526 ◽  
Author(s):  
R. Kanthasamy ◽  
I. K. Mbaraka ◽  
B. H. Shanks ◽  
S. C. Larsen
Keyword(s):  
Solid State ◽  
Sulfonic Acid ◽  
Mas Nmr ◽  
Nmr Studies

scholarly journals Characterization of nucleosome sediments for protein interaction studies by solid-state NMR spectroscopy

2021 ◽  
Author(s):  
Ulric B. le Paige ◽  
ShengQi Xiang ◽  
Marco M. R. M. Hendrix ◽  
Yi Zhang ◽  
Markus Weingarth ◽  
...  
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Solid State Nmr ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Dense Phase ◽  
Binding Studies ◽  
Nmr Studies ◽  
Solid State Nmr Spectroscopy ◽  
Wide Range

Abstract. Regulation of DNA-templated processes such as gene transcription and DNA repair depend on the interaction of a wide range of proteins to the nucleosome, the fundamental building block of chromatin. Both solution and solid-state NMR spectroscopy have become an attractive approach to study the dynamics and interactions of nucleosomes, despite their high molecular weight of ~200 kDa. For solid-state NMR (ssNMR) studies, dilute solutions of nucleosomes are converted to a dense phase by sedimentation or precipitation. Since nucleosomes are known to self-associate, these dense phases may induce extensive interactions between nucleosomes, which could interfere with protein binding studies. Here, we characterized the packing of nucleosomes in the dense phase created by sedimentation using NMR and small-angle x-ray scattering (SAXS) experiments. We found that nucleosome sediments are gels with variable degrees of solidity, have nucleosome concentration close to that found in crystals, and are stable for weeks under high-speed magic angle spinning (MAS). Furthermore, SAXS data recorded on recovered sediments indicate that there is no pronounced long-range ordering of nucleosomes in the sediment. Finally, we show that the sedimentation approach can also be used to study low affinity protein interactions with the nucleosome. Together, our results give new insights into the sample characteristics of nucleosome sediments for ssNMR studies and illustrate the broad applicability of sedimentation-based NMR studies.

Coordination Polymers Based on [Cp*Fe(η5-P5)]: Solid-State Structure and MAS NMR Studies

2011 ◽  
Vol 18 (4) ◽  
pp. 1168-1179 ◽  
Author(s):  
Fabian Dielmann ◽  
Andrea Schindler ◽  
Sabine Scheuermayer ◽  
Junfeng Bai ◽  
Roger Merkle ◽  
...  
Keyword(s):  
Solid State ◽  
Coordination Polymers ◽  
Mas Nmr ◽  
State Structure ◽  
Nmr Studies ◽  
Solid State Structure

Neutron diffraction and11B solid state NMR studies of the crystal structure of B-doped mullite

2013 ◽  
pp. 130521045435006
Author(s):  
Hanna Lührs ◽  
Anatoliy Senyshyn ◽  
Scott P. King ◽  
John V. Hanna ◽  
Hartmut Schneider ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Neutron Diffraction ◽  
Solid State Nmr ◽  
Nmr Studies
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