Understanding proton magnetic shielding in the benzene molecule

According to the ring current model quoted in textbooks of nuclear magnetic resonance spectroscopy, the downfield chemical shifts of hydrogen nuclei in aromatic molecules is due to intense delocalized currents induced in the π-electron cloud by a magnetic field at right angles to the molecular plane...

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Autores principales: Ferraro, M.B., Lazzeretti, P., Viglione, R.G., Zanasi, R.
Formato: JOUR
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Acceso en línea:http://hdl.handle.net/20.500.12110/paper_00092614_v390_n1-3_p268_Ferraro
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spelling todo:paper_00092614_v390_n1-3_p268_Ferraro2023-10-03T14:08:22Z Understanding proton magnetic shielding in the benzene molecule Ferraro, M.B. Lazzeretti, P. Viglione, R.G. Zanasi, R. aromatic compound benzene carbon proton article density functional theory electric current electron model molecular mechanics molecule phenomenology proton nuclear magnetic resonance According to the ring current model quoted in textbooks of nuclear magnetic resonance spectroscopy, the downfield chemical shifts of hydrogen nuclei in aromatic molecules is due to intense delocalized currents induced in the π-electron cloud by a magnetic field at right angles to the molecular plane. By using the Biot-Savart law, it was found that the delocalized ring currents deshield the out-of-plane component of proton shielding tensor via an essentially local mechanism taking place in the close vicinity of protons. The π ring currents over distant carbons shield the protons. π and σ electrons deshield benzene protons via different mechanisms clearly observed in plots of the shielding density function defined in the text. These results provide a novel interpretation of the phenomenology and suggest that the familiar model for interpreting chemical shifts of aromatics should be revised. © 2004 Published by Elsevier B.V. Fil:Ferraro, M.B. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00092614_v390_n1-3_p268_Ferraro
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic aromatic compound
benzene
carbon
proton
article
density functional theory
electric current
electron
model
molecular mechanics
molecule
phenomenology
proton nuclear magnetic resonance
spellingShingle aromatic compound
benzene
carbon
proton
article
density functional theory
electric current
electron
model
molecular mechanics
molecule
phenomenology
proton nuclear magnetic resonance
Ferraro, M.B.
Lazzeretti, P.
Viglione, R.G.
Zanasi, R.
Understanding proton magnetic shielding in the benzene molecule
topic_facet aromatic compound
benzene
carbon
proton
article
density functional theory
electric current
electron
model
molecular mechanics
molecule
phenomenology
proton nuclear magnetic resonance
description According to the ring current model quoted in textbooks of nuclear magnetic resonance spectroscopy, the downfield chemical shifts of hydrogen nuclei in aromatic molecules is due to intense delocalized currents induced in the π-electron cloud by a magnetic field at right angles to the molecular plane. By using the Biot-Savart law, it was found that the delocalized ring currents deshield the out-of-plane component of proton shielding tensor via an essentially local mechanism taking place in the close vicinity of protons. The π ring currents over distant carbons shield the protons. π and σ electrons deshield benzene protons via different mechanisms clearly observed in plots of the shielding density function defined in the text. These results provide a novel interpretation of the phenomenology and suggest that the familiar model for interpreting chemical shifts of aromatics should be revised. © 2004 Published by Elsevier B.V.
format JOUR
author Ferraro, M.B.
Lazzeretti, P.
Viglione, R.G.
Zanasi, R.
author_facet Ferraro, M.B.
Lazzeretti, P.
Viglione, R.G.
Zanasi, R.
author_sort Ferraro, M.B.
title Understanding proton magnetic shielding in the benzene molecule
title_short Understanding proton magnetic shielding in the benzene molecule
title_full Understanding proton magnetic shielding in the benzene molecule
title_fullStr Understanding proton magnetic shielding in the benzene molecule
title_full_unstemmed Understanding proton magnetic shielding in the benzene molecule
title_sort understanding proton magnetic shielding in the benzene molecule
url http://hdl.handle.net/20.500.12110/paper_00092614_v390_n1-3_p268_Ferraro
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