Academic Journal
Comparing Cosine and Sine Functions for Calculating the Magnetic Shielding of 29 Si Nuclei across Siliceous Zeolites
| العنوان: | Comparing Cosine and Sine Functions for Calculating the Magnetic Shielding of 29 Si Nuclei across Siliceous Zeolites |
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| المؤلفون: | A. A. Rybakov, D. P. Vercauteren, A. V. Larin |
| سنة النشر: | 2023 |
| مصطلحات موضوعية: | Cell Biology, Molecular Biology, Neuroscience, Physiology, Cancer, Science Policy, Mental Health, Computational Biology, Environmental Sciences not elsewhere classified, Biological Sciences not elsewhere classified, Chemical Sciences not elsewhere classified, Physical Sciences not elsewhere classified, Information Systems not elsewhere classified, typically approximated using, similar high level, final conclusion regarding, magnetic isotropic δ, chemical shift anisotropies, σ (< sup, ⟨ si –, – si ⟩, – si angles, – si angle, averaged si –, 29 , four candidate functions, five zeolite structures, – si, si –, five structures |
| الوصف: | 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( 29 Si) 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 Q 1 (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 Q 1 (O) versus sin(Si–O–Si) demonstrated a similar high level of accuracy for Q 1 (O) in the zeolites. The sin(⟨Si–O–Si⟩) function for the magnetic isotropic δ iso ( 29 Si) 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( 29 Si) chemical shifts between four candidate functions is linked to the distribution of Si–O bond lengths in the zeolites. |
| نوع الوثيقة: | article in journal/newspaper |
| اللغة: | unknown |
| Relation: | https://figshare.com/articles/journal_contribution/Comparing_Cosine_and_Sine_Functions_for_Calculating_the_Magnetic_Shielding_of_sup_29_sup_Si_Nuclei_across_Siliceous_Zeolites/24773160 |
| DOI: | 10.1021/acs.jpcc.3c04616.s001 |
| الاتاحة: | https://doi.org/10.1021/acs.jpcc.3c04616.s001 https://figshare.com/articles/journal_contribution/Comparing_Cosine_and_Sine_Functions_for_Calculating_the_Magnetic_Shielding_of_sup_29_sup_Si_Nuclei_across_Siliceous_Zeolites/24773160 |
| Rights: | CC BY-NC 4.0 |
| رقم الانضمام: | edsbas.96820B03 |
| قاعدة البيانات: | BASE |
| DOI: | 10.1021/acs.jpcc.3c04616.s001 |
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