Natural J coupling (NJC) analysis of the electron lone pair effect on NMR couplings: Part 1. the lone pair orientation effect of an α-nitrogen atom on1J(C,C) couplings

The known lone pair orientation effect of an α-nitrogen atom on 1J(C,C) couplings was studied using the natural J coupling (NJC) dissection method for the Fermi contact (FC) term. This dissection was performed at the DFT-B3LYP level using three different basis sets. It was verified that non-contact...

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Autores principales: Barone, Verónica, Peralta, Juan Ernesto, Contreras, Rubén Horacio
Publicado: 2001
Materias:
Bond contributions
Indirect spin-spin couplings
Lone-pair effect
Natural j couplings
Nbo interactions
NMR
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_07491581_v39_n10_p600_Barone
http://hdl.handle.net/20.500.12110/paper_07491581_v39_n10_p600_Barone
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Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id paper:paper_07491581_v39_n10_p600_Barone
record_format dspace
spelling paper:paper_07491581_v39_n10_p600_Barone2023-06-08T15:45:34Z Natural J coupling (NJC) analysis of the electron lone pair effect on NMR couplings: Part 1. the lone pair orientation effect of an α-nitrogen atom on1J(C,C) couplings Barone, Verónica Peralta, Juan Ernesto Contreras, Rubén Horacio Bond contributions Indirect spin-spin couplings Lone-pair effect Natural j couplings Nbo interactions NMR The known lone pair orientation effect of an α-nitrogen atom on 1J(C,C) couplings was studied using the natural J coupling (NJC) dissection method for the Fermi contact (FC) term. This dissection was performed at the DFT-B3LYP level using three different basis sets. It was verified that non-contact contributions, which are much smaller than the FC term, do not depend on the orientation of the N lone pair. Acetone oxime (1), protonated acetone oxime (2) and ethylamine (3), were taken as model compounds to perform this study. In 1 the difference between 1J(Z) and 1J(E) is mainly determined by three NJC terms, i.e the nitrogen lone pair, the carbon-carbon bond containing the coupled carbon atoms and the carbon inner core orbitals contributions. In 3 the angular dependence of 1J(C,C) vs the amine group conformation is dominated by the same three contributions that define the 1J(Z) and 1J(E) difference in 1. Copyright © 2001 John Wiley & Sons, Ltd. Fil:Barone, V. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Peralta, J.E. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Contreras, R.H. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2001 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_07491581_v39_n10_p600_Barone http://hdl.handle.net/20.500.12110/paper_07491581_v39_n10_p600_Barone
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Bond contributions
Indirect spin-spin couplings
Lone-pair effect
Natural j couplings
Nbo interactions
NMR
spellingShingle Bond contributions
Indirect spin-spin couplings
Lone-pair effect
Natural j couplings
Nbo interactions
NMR
Barone, Verónica
Peralta, Juan Ernesto
Contreras, Rubén Horacio
Natural J coupling (NJC) analysis of the electron lone pair effect on NMR couplings: Part 1. the lone pair orientation effect of an α-nitrogen atom on1J(C,C) couplings
topic_facet Bond contributions
Indirect spin-spin couplings
Lone-pair effect
Natural j couplings
Nbo interactions
NMR
description The known lone pair orientation effect of an α-nitrogen atom on 1J(C,C) couplings was studied using the natural J coupling (NJC) dissection method for the Fermi contact (FC) term. This dissection was performed at the DFT-B3LYP level using three different basis sets. It was verified that non-contact contributions, which are much smaller than the FC term, do not depend on the orientation of the N lone pair. Acetone oxime (1), protonated acetone oxime (2) and ethylamine (3), were taken as model compounds to perform this study. In 1 the difference between 1J(Z) and 1J(E) is mainly determined by three NJC terms, i.e the nitrogen lone pair, the carbon-carbon bond containing the coupled carbon atoms and the carbon inner core orbitals contributions. In 3 the angular dependence of 1J(C,C) vs the amine group conformation is dominated by the same three contributions that define the 1J(Z) and 1J(E) difference in 1. Copyright © 2001 John Wiley & Sons, Ltd.
author Barone, Verónica
Peralta, Juan Ernesto
Contreras, Rubén Horacio
author_facet Barone, Verónica
Peralta, Juan Ernesto
Contreras, Rubén Horacio
author_sort Barone, Verónica
title Natural J coupling (NJC) analysis of the electron lone pair effect on NMR couplings: Part 1. the lone pair orientation effect of an α-nitrogen atom on1J(C,C) couplings
title_short Natural J coupling (NJC) analysis of the electron lone pair effect on NMR couplings: Part 1. the lone pair orientation effect of an α-nitrogen atom on1J(C,C) couplings
title_full Natural J coupling (NJC) analysis of the electron lone pair effect on NMR couplings: Part 1. the lone pair orientation effect of an α-nitrogen atom on1J(C,C) couplings
title_fullStr Natural J coupling (NJC) analysis of the electron lone pair effect on NMR couplings: Part 1. the lone pair orientation effect of an α-nitrogen atom on1J(C,C) couplings
title_full_unstemmed Natural J coupling (NJC) analysis of the electron lone pair effect on NMR couplings: Part 1. the lone pair orientation effect of an α-nitrogen atom on1J(C,C) couplings
title_sort natural j coupling (njc) analysis of the electron lone pair effect on nmr couplings: part 1. the lone pair orientation effect of an α-nitrogen atom on1j(c,c) couplings
publishDate 2001
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_07491581_v39_n10_p600_Barone
http://hdl.handle.net/20.500.12110/paper_07491581_v39_n10_p600_Barone
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AT peraltajuanernesto naturaljcouplingnjcanalysisoftheelectronlonepaireffectonnmrcouplingspart1thelonepairorientationeffectofananitrogenatomon1jcccouplings
AT contrerasrubenhoracio naturaljcouplingnjcanalysisoftheelectronlonepaireffectonnmrcouplingspart1thelonepairorientationeffectofananitrogenatomon1jcccouplings
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