Charge delocalization in Z-isomers of (4α → 6”, 2α → 0 → 1”)-phenylflavans with R = H, OH and OCH3. Effects on bond dissociation enthalpies and ionization potentials

Autores
Lobayan, Rosana Maria; Bentz, Erika Natalia; Jubert, Alicia Haydee; Pomilio, Alicia Beatriz
Año de publicación
2013
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
The (2 alpha-O-1´´)-bridged 4-phenylflavans comprise an interesting structure, included in natural antioxidants such as simple and dimeric A-type proanthocyanidins, catechins and condensed tannins. This work concerns the analysis of the stereoelectronic effects induced by substitution with R = H, OH and OCH3 in Z-isomers of (4alpha-6´´,2alpha- O-1´´)-phenylflavans using density functional methods in order to deepen the understanding of the molecular and structural properties of these compounds. A fully relaxed scan procedure was performed. A topological study of the molecular charge density (Bader theory, Atoms in Molecules) and a Natural Bond Orbital (NBO) analysis at the B3LYP/6-311++G** level were carried out. The stereochemistry of the molecules was discussed in detail focusing on the factors related to their antioxidant properties. Bond dissociation enthalpies (BDEs), ionization potentials (IPs) and electron affinities (EAs) were calculated for the lowest energy conformers. The Nuclear Magnetic Resonance (NMR) chemical shifts were also calculated at the B3LYP/6-31G** level, and compared with the earlier reported experimental values, showing that the thermodynamically most stable conformer is also the most stable kinetically. The effects of substituents on chemical shifts were quantified. Through a donor acceptor map a qualitative comparison among the studied compounds is given. The lower (higher) BDE (IP) values found for R = OH (4alpha-6´´,2alpha-O-1´´)-phenylflavans, were explained herein by specific mechanisms of charge delocalization. These findings highlight the key role played by hyperconjugative interactions in the stereoelectronic effects induced by substitution as an important factor in understanding the associated values of BDEs and IPs.
Fil: Lobayan, Rosana Maria. Universidad de la Cuenca del Plata. Facultad de Ingenieria; Argentina. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Departamento de Fisica y Quimica; Argentina
Fil: Bentz, Erika Natalia. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Departamento de Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; Argentina
Fil: Jubert, Alicia Haydee. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Química Inorgánica; Argentina
Fil: Pomilio, Alicia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular; Argentina
Materia
Ionization Potentials
Proanthocyanidins
Density Functional Theory
Atoms in Molecules
Natural Bond Orbital Analysis
Bond Dissociation Enthalpies
Nivel de accesibilidad
acceso abierto
Condiciones de uso
https://creativecommons.org/licenses/by-nc-nd/2.5/ar/
Repositorio
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/8567
Acceder
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oai_identifier_str oai:ri.conicet.gov.ar:11336/8567
network_acronym_str CONICETDig
repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling Charge delocalization in Z-isomers of (4α → 6”, 2α → 0 → 1”)-phenylflavans with R = H, OH and OCH3. Effects on bond dissociation enthalpies and ionization potentialsLobayan, Rosana MariaBentz, Erika NataliaJubert, Alicia HaydeePomilio, Alicia BeatrizIonization PotentialsProanthocyanidinsDensity Functional TheoryAtoms in MoleculesNatural Bond Orbital AnalysisBond Dissociation Enthalpieshttps://purl.org/becyt/ford/1.3https://purl.org/becyt/ford/1https://purl.org/becyt/ford/1.4https://purl.org/becyt/ford/1The (2 alpha-O-1´´)-bridged 4-phenylflavans comprise an interesting structure, included in natural antioxidants such as simple and dimeric A-type proanthocyanidins, catechins and condensed tannins. This work concerns the analysis of the stereoelectronic effects induced by substitution with R = H, OH and OCH3 in Z-isomers of (4alpha-6´´,2alpha- O-1´´)-phenylflavans using density functional methods in order to deepen the understanding of the molecular and structural properties of these compounds. A fully relaxed scan procedure was performed. A topological study of the molecular charge density (Bader theory, Atoms in Molecules) and a Natural Bond Orbital (NBO) analysis at the B3LYP/6-311++G** level were carried out. The stereochemistry of the molecules was discussed in detail focusing on the factors related to their antioxidant properties. Bond dissociation enthalpies (BDEs), ionization potentials (IPs) and electron affinities (EAs) were calculated for the lowest energy conformers. The Nuclear Magnetic Resonance (NMR) chemical shifts were also calculated at the B3LYP/6-31G** level, and compared with the earlier reported experimental values, showing that the thermodynamically most stable conformer is also the most stable kinetically. The effects of substituents on chemical shifts were quantified. Through a donor acceptor map a qualitative comparison among the studied compounds is given. The lower (higher) BDE (IP) values found for R = OH (4alpha-6´´,2alpha-O-1´´)-phenylflavans, were explained herein by specific mechanisms of charge delocalization. These findings highlight the key role played by hyperconjugative interactions in the stereoelectronic effects induced by substitution as an important factor in understanding the associated values of BDEs and IPs.Fil: Lobayan, Rosana Maria. Universidad de la Cuenca del Plata. Facultad de Ingenieria; Argentina. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Departamento de Fisica y Quimica; ArgentinaFil: Bentz, Erika Natalia. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Departamento de Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; ArgentinaFil: Jubert, Alicia Haydee. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Química Inorgánica; ArgentinaFil: Pomilio, Alicia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular; ArgentinaElsevier2013-02info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/8567Lobayan, Rosana Maria; Bentz, Erika Natalia; Jubert, Alicia Haydee; Pomilio, Alicia Beatriz; Charge delocalization in Z-isomers of (4α → 6”, 2α → 0 → 1”)-phenylflavans with R = H, OH and OCH3. Effects on bond dissociation enthalpies and ionization potentials; Elsevier; Computational and Theoretical Chemistry; 1006; 2-2013; 37-462210-271Xenginfo:eu-repo/semantics/altIdentifier/doi/10.1016/j.comptc.2012.11.008info:eu-repo/semantics/altIdentifier/url/http://www.sciencedirect.com/science/article/pii/S2210271X12005786info:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-nd/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-10-15T15:40:37Zoai:ri.conicet.gov.ar:11336/8567instacron:CONICETInstitucionalhttp://ri.conicet.gov.ar/Organismo científico-tecnológicoNo correspondehttp://ri.conicet.gov.ar/oai/requestdasensio@conicet.gov.ar; lcarlino@conicet.gov.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:34982025-10-15 15:40:37.736CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Charge delocalization in Z-isomers of (4α → 6”, 2α → 0 → 1”)-phenylflavans with R = H, OH and OCH3. Effects on bond dissociation enthalpies and ionization potentials
title Charge delocalization in Z-isomers of (4α → 6”, 2α → 0 → 1”)-phenylflavans with R = H, OH and OCH3. Effects on bond dissociation enthalpies and ionization potentials
spellingShingle Charge delocalization in Z-isomers of (4α → 6”, 2α → 0 → 1”)-phenylflavans with R = H, OH and OCH3. Effects on bond dissociation enthalpies and ionization potentials
Lobayan, Rosana Maria
Ionization Potentials
Proanthocyanidins
Density Functional Theory
Atoms in Molecules
Natural Bond Orbital Analysis
Bond Dissociation Enthalpies
title_short Charge delocalization in Z-isomers of (4α → 6”, 2α → 0 → 1”)-phenylflavans with R = H, OH and OCH3. Effects on bond dissociation enthalpies and ionization potentials
title_full Charge delocalization in Z-isomers of (4α → 6”, 2α → 0 → 1”)-phenylflavans with R = H, OH and OCH3. Effects on bond dissociation enthalpies and ionization potentials
title_fullStr Charge delocalization in Z-isomers of (4α → 6”, 2α → 0 → 1”)-phenylflavans with R = H, OH and OCH3. Effects on bond dissociation enthalpies and ionization potentials
title_full_unstemmed Charge delocalization in Z-isomers of (4α → 6”, 2α → 0 → 1”)-phenylflavans with R = H, OH and OCH3. Effects on bond dissociation enthalpies and ionization potentials
title_sort Charge delocalization in Z-isomers of (4α → 6”, 2α → 0 → 1”)-phenylflavans with R = H, OH and OCH3. Effects on bond dissociation enthalpies and ionization potentials
dc.creator.none.fl_str_mv Lobayan, Rosana Maria
Bentz, Erika Natalia
Jubert, Alicia Haydee
Pomilio, Alicia Beatriz
author Lobayan, Rosana Maria
author_facet Lobayan, Rosana Maria
Bentz, Erika Natalia
Jubert, Alicia Haydee
Pomilio, Alicia Beatriz
author_role author
author2 Bentz, Erika Natalia
Jubert, Alicia Haydee
Pomilio, Alicia Beatriz
author2_role author
author
author
dc.subject.none.fl_str_mv Ionization Potentials
Proanthocyanidins
Density Functional Theory
Atoms in Molecules
Natural Bond Orbital Analysis
Bond Dissociation Enthalpies
topic Ionization Potentials
Proanthocyanidins
Density Functional Theory
Atoms in Molecules
Natural Bond Orbital Analysis
Bond Dissociation Enthalpies
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.3
https://purl.org/becyt/ford/1
https://purl.org/becyt/ford/1.4
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv The (2 alpha-O-1´´)-bridged 4-phenylflavans comprise an interesting structure, included in natural antioxidants such as simple and dimeric A-type proanthocyanidins, catechins and condensed tannins. This work concerns the analysis of the stereoelectronic effects induced by substitution with R = H, OH and OCH3 in Z-isomers of (4alpha-6´´,2alpha- O-1´´)-phenylflavans using density functional methods in order to deepen the understanding of the molecular and structural properties of these compounds. A fully relaxed scan procedure was performed. A topological study of the molecular charge density (Bader theory, Atoms in Molecules) and a Natural Bond Orbital (NBO) analysis at the B3LYP/6-311++G** level were carried out. The stereochemistry of the molecules was discussed in detail focusing on the factors related to their antioxidant properties. Bond dissociation enthalpies (BDEs), ionization potentials (IPs) and electron affinities (EAs) were calculated for the lowest energy conformers. The Nuclear Magnetic Resonance (NMR) chemical shifts were also calculated at the B3LYP/6-31G** level, and compared with the earlier reported experimental values, showing that the thermodynamically most stable conformer is also the most stable kinetically. The effects of substituents on chemical shifts were quantified. Through a donor acceptor map a qualitative comparison among the studied compounds is given. The lower (higher) BDE (IP) values found for R = OH (4alpha-6´´,2alpha-O-1´´)-phenylflavans, were explained herein by specific mechanisms of charge delocalization. These findings highlight the key role played by hyperconjugative interactions in the stereoelectronic effects induced by substitution as an important factor in understanding the associated values of BDEs and IPs.
Fil: Lobayan, Rosana Maria. Universidad de la Cuenca del Plata. Facultad de Ingenieria; Argentina. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Departamento de Fisica y Quimica; Argentina
Fil: Bentz, Erika Natalia. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Departamento de Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; Argentina
Fil: Jubert, Alicia Haydee. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Química Inorgánica; Argentina
Fil: Pomilio, Alicia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular; Argentina
description The (2 alpha-O-1´´)-bridged 4-phenylflavans comprise an interesting structure, included in natural antioxidants such as simple and dimeric A-type proanthocyanidins, catechins and condensed tannins. This work concerns the analysis of the stereoelectronic effects induced by substitution with R = H, OH and OCH3 in Z-isomers of (4alpha-6´´,2alpha- O-1´´)-phenylflavans using density functional methods in order to deepen the understanding of the molecular and structural properties of these compounds. A fully relaxed scan procedure was performed. A topological study of the molecular charge density (Bader theory, Atoms in Molecules) and a Natural Bond Orbital (NBO) analysis at the B3LYP/6-311++G** level were carried out. The stereochemistry of the molecules was discussed in detail focusing on the factors related to their antioxidant properties. Bond dissociation enthalpies (BDEs), ionization potentials (IPs) and electron affinities (EAs) were calculated for the lowest energy conformers. The Nuclear Magnetic Resonance (NMR) chemical shifts were also calculated at the B3LYP/6-31G** level, and compared with the earlier reported experimental values, showing that the thermodynamically most stable conformer is also the most stable kinetically. The effects of substituents on chemical shifts were quantified. Through a donor acceptor map a qualitative comparison among the studied compounds is given. The lower (higher) BDE (IP) values found for R = OH (4alpha-6´´,2alpha-O-1´´)-phenylflavans, were explained herein by specific mechanisms of charge delocalization. These findings highlight the key role played by hyperconjugative interactions in the stereoelectronic effects induced by substitution as an important factor in understanding the associated values of BDEs and IPs.
publishDate 2013
dc.date.none.fl_str_mv 2013-02
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
http://purl.org/coar/resource_type/c_6501
info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/11336/8567
Lobayan, Rosana Maria; Bentz, Erika Natalia; Jubert, Alicia Haydee; Pomilio, Alicia Beatriz; Charge delocalization in Z-isomers of (4α → 6”, 2α → 0 → 1”)-phenylflavans with R = H, OH and OCH3. Effects on bond dissociation enthalpies and ionization potentials; Elsevier; Computational and Theoretical Chemistry; 1006; 2-2013; 37-46
2210-271X
url http://hdl.handle.net/11336/8567
identifier_str_mv Lobayan, Rosana Maria; Bentz, Erika Natalia; Jubert, Alicia Haydee; Pomilio, Alicia Beatriz; Charge delocalization in Z-isomers of (4α → 6”, 2α → 0 → 1”)-phenylflavans with R = H, OH and OCH3. Effects on bond dissociation enthalpies and ionization potentials; Elsevier; Computational and Theoretical Chemistry; 1006; 2-2013; 37-46
2210-271X
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/doi/10.1016/j.comptc.2012.11.008
info:eu-repo/semantics/altIdentifier/url/http://www.sciencedirect.com/science/article/pii/S2210271X12005786
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
https://creativecommons.org/licenses/by-nc-nd/2.5/ar/
eu_rights_str_mv openAccess
rights_invalid_str_mv https://creativecommons.org/licenses/by-nc-nd/2.5/ar/
dc.format.none.fl_str_mv application/pdf
application/pdf
application/pdf
dc.publisher.none.fl_str_mv Elsevier
publisher.none.fl_str_mv Elsevier
dc.source.none.fl_str_mv reponame:CONICET Digital (CONICET)
instname:Consejo Nacional de Investigaciones Científicas y Técnicas
reponame_str CONICET Digital (CONICET)
collection CONICET Digital (CONICET)
instname_str Consejo Nacional de Investigaciones Científicas y Técnicas
repository.name.fl_str_mv CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicas
repository.mail.fl_str_mv dasensio@conicet.gov.ar; lcarlino@conicet.gov.ar
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score 13.22299

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