Designed synthesis of an extra-large pore zeolite with a 14-membered ring channel via supramolecular assembly templating approach

2019 ◽  
Vol 290 ◽  
pp. 109654
Author(s):  
Wen-Wen Zi ◽  
Zihao Gao ◽  
Jun Zhang ◽  
Jing-Hui Lv ◽  
Bao-Xun Zhao ◽  
...  
Keyword(s):  
Supramolecular Assembly ◽  
Membered Ring ◽  
Large Pore ◽  
Ring Channel ◽  
Designed Synthesis

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.

Synchrotron powder diffraction characterization of the zeolite-based (p-N,N-dimethylnitroaniline–mordenite) guest–host phase

2008 ◽  
Vol 64 (6) ◽  
pp. 713-724 ◽  
Author(s):  
Florence Porcher ◽  
Elena Borissenko ◽  
Mohamed Souhassou ◽  
Masaki Takata ◽  
Kenichi Kato ◽  
...  
Keyword(s):  
Powder Diffraction ◽  
Dipole Moments ◽  
Membered Ring ◽  
Unit Cell Parameters ◽  
Cell Parameters ◽  
Crystallographic Study ◽  
Synchrotron Powder Diffraction ◽  
Ring Channel ◽  
New Phase

The crystal structure of a new phase consisting of the inclusion of the hyperpolarizable molecule p-N,N-dimethylnitroaniline (dimethyl-para-nitroaniline or dmpNA) in the large-pore zeolite mordenite (MOR) has been determined from high-resolution synchrotron powder diffraction at 300 and 90 K. The unit-cell parameters and space group at 300 K are similar to those of as-synthesized mordenite. The crystallographic study indicates that the MOR straight channels are almost fully loaded with molecules that are disordered over eight symmetry-related sites. As expected, the molecules are located in the large 12-membered ring channel, at the intersection with the secondary eight-membered channel with which they might form hydrogen bonds. The elongation axes (and then the dipole moments) of the molecules are slightly tilted (28.57°) from [001]. The configuration found suggests an interaction of dmpNA with framework O atoms through its methyl groups.

Mu-28: an open-framework fluorogallophosphate with a three-dimensional 12-membered ring channel system

2004 ◽  
Vol 177 (10) ◽  
pp. 3721-3728 ◽  
Author(s):  
Ludovic Josien ◽  
Angélique Simon-Masseron ◽  
Volker Gramlich ◽  
Florence Porcher ◽  
Joël Patarin
Keyword(s):  
Three Dimensional ◽  
Membered Ring ◽  
Channel System ◽  
Open Framework ◽  
Ring Channel

Designed synthesis of large-pore mesoporous silica–zirconia thin films with high mixing degree and tunable cubic or 2D-hexagonal mesostructure

2004 ◽  
Vol 14 (12) ◽  
pp. 1879-1886 ◽  
Author(s):  
Galo J. A. A. Soler-Illia ◽  
Eduardo L. Crepaldi ◽  
David Grosso ◽  
Clément Sanchez
Keyword(s):  
Thin Films ◽  
Mesoporous Silica ◽  
Large Pore ◽  
Designed Synthesis

scholarly journals Designed synthesis of large-pore crystalline polyimide covalent organic frameworks

2014 ◽  
Vol 5 (1) ◽  
Author(s):  
Qianrong Fang ◽  
Zhongbin Zhuang ◽  
Shuang Gu ◽  
Robert B. Kaspar ◽  
Jie Zheng ◽  
...  
Keyword(s):  
Covalent Organic Frameworks ◽  
Large Pore ◽  
Designed Synthesis
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