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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Autor principal:	Ferraro, Marta Beatriz
Publicado:	2004
Materias:	aromatic compound benzene carbon proton article density functional theory electric current electron model molecular mechanics molecule phenomenology proton nuclear magnetic resonance
Acceso en línea:	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00092614_v390_n1-3_p268_Ferraro http://hdl.handle.net/20.500.12110/paper_00092614_v390_n1-3_p268_Ferraro
Aporte de:	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires

id	paper:paper_00092614_v390_n1-3_p268_Ferraro
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spelling	paper:paper_00092614_v390_n1-3_p268_Ferraro2023-06-08T14:33:47Z Understanding proton magnetic shielding in the benzene molecule Ferraro, Marta Beatriz 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. 2004 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00092614_v390_n1-3_p268_Ferraro 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, Marta Beatriz 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.
author	Ferraro, Marta Beatriz
author_facet	Ferraro, Marta Beatriz
author_sort	Ferraro, Marta Beatriz
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
publishDate	2004
url	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00092614_v390_n1-3_p268_Ferraro http://hdl.handle.net/20.500.12110/paper_00092614_v390_n1-3_p268_Ferraro
work_keys_str_mv	AT ferraromartabeatriz understandingprotonmagneticshieldinginthebenzenemolecule
_version_	1768542531976429568

Understanding proton magnetic shielding in the benzene molecule

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