Ubiquitous Presence of Intermolecular CH…O Hydrogen Bonds in As‐synthesized Host‐Guest Zeolite Materials

Al-Nahari, Shadi; Ata, Karima; Mineva, Tzonka; Alonso, Bruno

doi:10.1002/slct.202102771

Cited by 3 publications

(3 citation statements)

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“…This second type of disorder can be related to the positioning of TPEA inside the zeolite. As mentioned, the nature and structure of the organic molecules hosted in silicalite-1 influence the geometry of the silica framework around them thanks to the interplay of various effective intermolecular interactions (van der Waals, Coulomb, hydrogen bonds). − These molecular effects are observed at a long-range length scale, typically by XRD, but their local nature obviously operates at the short range. Hence, each specific positioning of an ethyl arm will lead to a specific and local geometrical deformation of the silica framework.…”

Section: Results and Discussionmentioning

confidence: 99%

“…As mentioned, the nature and structure of the organic molecules hosted in silicalite-1 influences the geometry of the silica framework around them thanks to the interplay of various effective intermolecular interactions (van der Waals, Coulomb, hydrogen bonds). [85][86][87][88] These molecular effects are observed at a long-range length scale, typically by XRD, but their local nature obviously operates at the short range.…”

Section: Nature Of the Local Geometrical Disorder In The Zeolite Fram...mentioning

confidence: 99%

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Host–Guest Silicalite-1 Zeolites: Correlated Disorder and Phase Transition Inhibition by a Small Guest Modification

et al. 2021

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We have investigated the nature and extent of nanoscale disorder in prototypical host-guest zeolites, made of silicalite-1 (host) and organic structure directing agent (OSDA, guest). The four different selected OSDA-silicalite-1 differ in: the mineralizing agent used (Fvs. OH -), the synthesis' method (hydrothermal vs. solvent-free) and the OSDA (tetrapropylammonium TPA vs. tripropylethylammonium TPEA). The comparison between TPA and TPEA, chemically similar but differing in their symmetry, is examined in great detail owing to the novel relationship found between the geometrical disorder and the monoclinic-orthorhombic (m-o) phase transition occurring at low temperature. Long-and short-range organization and ordering are characterized by complementary XRD, Raman and multinuclear NMR ( 13 C, 14 N, 29 Si). The possibility of the m-o transition is studied by all these techniques at variable low T. An in-depth study of the disorder is carried out by x-ray structure determination and 2D NMR 29 Si-29 Si INADEQUATE correlations, including an up-to-date analysis of anisotropic atomic displacement parameters and a new fitting approach to estimate correlated disorder from 2D NMR datasets. The collected results allow to demonstrate how the disorder created by the positioning of the less symmetric TPEA guest leads to a correlated geometrical disorder for half of the atom sites in the host framework that completely inhibits the m-o phase transition.

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Section: Results and Discussionmentioning

confidence: 99%

Section: Nature Of the Local Geometrical Disorder In The Zeolite Fram...mentioning

confidence: 99%

Host–Guest Silicalite-1 Zeolites: Correlated Disorder and Phase Transition Inhibition by a Small Guest Modification

et al. 2021

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“…The generalised gradient-corrected PBE approximation was used as the exchange correlation (XC) functional, augmented by the empirical London dispersion (D3) term with the Becke-Johnson damping function [48]. The optimised structural parameters of zeolites with OSDA, obtained with the Crystal code and all-electron databases, were found by us to agree well with the experimental bond distances and bond angles [49][50][51].…”

Section: Dft Computational Detailsmentioning

confidence: 83%

Regression Machine Learning Models Used to Predict DFT-Computed NMR Parameters of Zeolites

Gaumard

Dragún²,

Pedroza-Montero

et al. 2022

Computation

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Machine learning approaches can drastically decrease the computational time for the predictions of spectroscopic properties in materials, while preserving the quality of the computational approaches. We studied the performance of kernel-ridge regression (KRR) and gradient boosting regressor (GBR) models trained on the isotropic shielding values, computed with density-functional theory (DFT), in a series of different known zeolites containing out-of-frame metal cations or fluorine anion and organic structure-directing cations. The smooth overlap of atomic position descriptors were computed from the DFT-optimised Cartesian coordinates of each atoms in the zeolite crystal cells. The use of these descriptors as inputs in both machine learning regression methods led to the prediction of the DFT isotropic shielding values with mean errors within 0.6 ppm. The results showed that the GBR model scales better than the KRR model.

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Strength of London Dispersion Forces in Organic Structure Directing Agent—Zeolite Assemblies

Ata,

Mineva,

Alonso

2024

Molecules

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Herein, we study the London dispersion forces between organic structure directing agents (OSDAs)—here tetraalkyl-ammonium or -phosphonium molecules—and silica zeolite frameworks (FWs). We demonstrate that the interaction energy for these dispersion forces is correlated to the number of H atoms in OSDAs, irrespective of the structures of OSDAs or FWs, and of variations in charges and thermal motions. All calculations considered—DFT-D3 and BOMD undertaken by us, and molecular mechanics from an accessible database—led to the same trend. The mean energy of these dispersion forces is ca. −2 kcal.mol−1 per H for efficient H-O contacts.

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Ubiquitous Presence of Intermolecular CH…O Hydrogen Bonds in As‐synthesized Host‐Guest Zeolite Materials

Cited by 3 publications

References 41 publications

Host–Guest Silicalite-1 Zeolites: Correlated Disorder and Phase Transition Inhibition by a Small Guest Modification

Host–Guest Silicalite-1 Zeolites: Correlated Disorder and Phase Transition Inhibition by a Small Guest Modification

Regression Machine Learning Models Used to Predict DFT-Computed NMR Parameters of Zeolites

Strength of London Dispersion Forces in Organic Structure Directing Agent—Zeolite Assemblies

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