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Abstract
The relationship between the s-fraction of O orbitals, electronic density at the O lone pair, and Si-O-Si angles in the total magnetic shielding σ(29Si) of zeolite materials is typically approximated using the cos(⟨Si-O-Si⟩)/(cos(⟨Si-O-Si⟩) - 1) function, with the ⟨Si-O-Si⟩ being the averaged Si-O-Si angle over the four O neighbors of Si. In this work, an analogous sin(⟨Si-O-Si⟩) dependence is introduced based on the approximation of the absolute O dipoles Q1(O) versus the Si-O-Si angle in five zeolite structures (BEA, FER, GOO, ZSM-12, and ZSM-57). The models, along with α-quartz, were considered to evaluate the advantages of the effects on both chemical shifts and chemical shift anisotropies, as measured for α-quartz and ZSM-12. The decrease of the O dipole with the Si-O-Si angle is usually interpreted as a variation of the electronic density at the O lone pairs. The dependence of Q1(O) versus sin(Si-O-Si) demonstrated a similar high level of accuracy for Q1(O) in the zeolites. The sin(⟨Si-O-Si⟩) function for the magnetic isotropic δiso(29Si) chemical shifts was also demonstrated for some of the five structures. The final conclusion regarding a better approximation of the angular dependence of the σ(29Si) chemical shifts between four candidate functions is linked to the distribution of Si-O bond lengths in the zeolites.
Original language | English |
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Pages (from-to) | 24324-24338 |
Number of pages | 15 |
Journal | Journal of Physical Chemistry C: Nanomaterials and interfaces |
Volume | 127 |
Issue number | 50 |
DOIs | |
Publication status | Published - 21 Dec 2023 |
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Dive into the research topics of 'Comparing Cosine and Sine Functions for Calculating the Magnetic Shielding of 29Si Nuclei across Siliceous Zeolites'. Together they form a unique fingerprint.Projects
- 1 Finished
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CÉCI – Consortium of high performance computing centers
CHAMPAGNE, B. (PI), Lazzaroni, R. (PI), Geuzaine , C. (CoI), Chatelain, P. (CoI) & Knaepen, B. (CoI)
1/01/18 → 31/12/22
Project: Research
Equipment
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High Performance Computing Technology Platform
Champagne, B. (Manager)
Technological Platform High Performance ComputingFacility/equipment: Technological Platform