scholarly journals Ubiquitous Presence of Intermolecular CH…O Hydrogen Bonds in As-Synthesized Zeolite Materials

2021 ◽  
Author(s):  
Shadi Al Nahari ◽  
Karima Ata ◽  
Tzonka Mineva ◽  
Bruno Alonso
Keyword(s):  
Hydrogen Bonds ◽  
Dft Calculations ◽  
Organic Structure ◽  
Structure Directing Agents ◽  
Ubiquitous Presence

CH…O hydrogen bonds (HBs) are identified in all crystals of series of silica zeolites hosting cationic Organic Structure Directing agents. This finding is supported by experimental C-O distances and COSi angles’ distributions, and DFT calculations on representative structures. New insights are reported on the geometry and electrostatics of these HBs.<br>

scholarly journals Ubiquitous Presence of Intermolecular CH…O Hydrogen Bonds in As-Synthesized Zeolite Materials

2021 ◽  
Author(s):  
Shadi Al Nahari ◽  
Karima Ata ◽  
Tzonka Mineva ◽  
Bruno Alonso
Keyword(s):  
Hydrogen Bonds ◽  
Dft Calculations ◽  
Organic Structure ◽  
Structure Directing Agents ◽  
Ubiquitous Presence

CH…O hydrogen bonds (HBs) are identified in all crystals of series of silica zeolites hosting cationic Organic Structure Directing agents. This finding is supported by experimental C-O distances and COSi angles’ distributions, and DFT calculations on representative structures. New insights are reported on the geometry and electrostatics of these HBs.<br>

scholarly journals Alcohol-assisted synthesis of high-silica zeolites in the absence of organic structure-directing agents

2021 ◽  
Vol 42 (4) ◽  
pp. 563-570
Author(s):  
Huimin Luan ◽  
Chi Lei ◽  
Ye Ma ◽  
Qinming Wu ◽  
Longfeng Zhu ◽  
...  
Keyword(s):  
Organic Structure ◽  
High Silica ◽  
High Silica Zeolites ◽  
Structure Directing Agents

scholarly journals Cooperation/Competition between Halogen Bonds and Hydrogen Bonds in Complexes of 2,6-Diaminopyridines and X-CY3 (X = Cl, Br; Y = H, F)

Symmetry ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 766
Author(s):  
Barbara Bankiewicz ◽  
Marcin Palusiak
Keyword(s):  
Complex Formation ◽  
Hydrogen Bonds ◽  
Dft Calculations ◽  
Electrostatic Interactions ◽  
Dipole Moments ◽  
Main Role ◽  
Halogen Bonds ◽  
Topological Parameters ◽  
Leading Role ◽  
The Impact

The DFT calculations have been performed on a series of two-element complexes formed by substituted 2,6-diaminopyridine (R−PDA) and pyridine (R−Pyr) with X−CY3 molecules (where X = Cl, Br and Y = H, F). The primary aim of this study was to examine the intermolecular hydrogen and halogen bonds in the condition of their mutual coexistence. Symmetry/antisymmetry of the interrelation between three individual interactions is addressed. It appears that halogen bonds play the main role in the stabilization of the structures of the selected systems. However, the occurrence of one or two hydrogen bonds was associated with the favourable geometry of the complexes. Moreover, the impact of different substituent groups attached in the para position to the aromatic ring of the 2,6-diaminopyridine and pyridine on the character of the intermolecular hydrogen and halogen bonds was examined. The results indicate that the presence of electron-donating substituents strengthens the bonds. In turn, the presence of electron-withdrawing substituents reduces the strength of halogen bonds. Additionally, when hydrogen and halogen bonds lose their leading role in the complex formation, the nonspecific electrostatic interactions between dipole moments take their place. Analysis was based on geometric, energetic, and topological parameters of the studied systems.

scholarly journals Zeolite Synthesis Using Imidazolium Cations as Organic Structure-Directing Agents

2019 ◽  
Vol 10 (1) ◽  
pp. 303
Author(s):  
Paloma Vinaches ◽  
Sibele Pergher
Keyword(s):  
Research Study ◽  
Research Area ◽  
Zeolite Synthesis ◽  
New Materials ◽  
Imidazolium Cation ◽  
Organic Structure ◽  
Imidazolium Cations ◽  
Structure Directing Agents ◽  
Direction Effect

Imidazolium-derivative cations are very interesting molecules used as organic structure-directing agents (OSDAs) for zeolite synthesis, widening the possibilities of new materials and applications in this research area. In this review, the studies performed at LABPEMOL using this kind of compound are presented after a quick overview on imidazolium derivatives. The first zeolite synthesis results that started this research study were obtained with 1-butyl-3-methylimidazolium chloride. Then, the design of new OSDAs based on the imidazolium cation, such as 1,2,3-triethylimidazolium, 2-ethyl-1,3-dimethylimidazolium and 1,2,3-triethyl-4-methylimidazolium, is reported. Afterwards, the structure-direction effect caused by the introduction of heteroatoms with already-published imidazolium derivatives (for example, the Al3+ insertion into zeolite frameworks with two different OSDAs and the silicoaluminophosphate (SAPO) synthesis using 2-ethyl-1,3,4 trimethylimidazolium cations) is discussed. Finally, we also present a quick overview of some achievements of other laboratories.

scholarly journals Revisiting the seed-assisted synthesis of zeolites without organic structure-directing agents: insights from the CHA case

RSC Advances ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 5304-5315 ◽  
Author(s):  
Grandprix T. M. Kadja ◽  
Iftitah R. Kadir ◽  
Adroit T. N. Fajar ◽  
Veinardi Suendo ◽  
Rino R. Mukti
Keyword(s):  
Crystallization Behaviour ◽  
Structure Directing Agent ◽  
Organic Structure ◽  
Structure Directing Agents

Herein, the crystallization behaviour of the CHA zeolite synthesized via the seed-assisted method and in the absence of an organic structure-directing agent has been revisited.

Sign in / Sign up

Export Citation Format

Share Document