α-Sulfur or α-fluorine - Which is more stabilizing for a carbocation? A computational study of electrophilic addition to HFCCH(SMe) and FC(R1)CR2(SMe) and related model systems

Autores
Laali, Kenneth K.; Borosky, Gabriela Leonor
Año de publicación
2013
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Carbocations derived from protonation, methylation, and bromine addition to HFC55CH(SMe) (1) were studied by DFT [B3LYP/6-31G*, B3LYP/6-311G(3df,p), and B3LYP/aug-cc-pVTZ] and by MP2/6-31G* to examine relative carbocation stabilizing effects of a-SMe versus a-fluorine. The a-SMe carbocations 1aE+ and the unsymmetrical thiiranium ions 1cE+ were found to be considerably more stable than the corresponding a-fluorocarbenium ions 1bE+ . Study of protonation and methylation of FC(R1)55CR2(SMe) [R1 = H, R2 = SMe (2); R1 = F, R2 = H (3); R1 = F, R2 = SMe (4); R1 = Me, R2 = H (5); R1 = Me, R2 = SMe (6)] by B3LYP/6-31G* identified the corresponding unsymmetrical thiiranium cations as lowest energy minima, followed closely by the a-thiocarbenium ions. With 2, 4, and 6, skeletally rearranged a-thiocarbenium ions are formed by SMe migration. The a-SMe and the thiiranium cations are also favored relative to a- fluorocarbenium ions in protonation and methylation of the cyclic analogs 8 and 9. Computed NPA charges and the GIAO-derived 13C and 19F NMR chemical shifts underscore the significance of athiocarbocations and thiiranium ions in electrophilic addition to FC(R1)55CR2(SMe).
Fil: Laali, Kenneth K.. University of Florida; Estados Unidos
Fil: Borosky, Gabriela Leonor. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto de Investigaciones en Físicoquímica de Córdoba; Argentina
Materia
Α-F VERSUS Α-SME
CHARGE DELOCALIZATION
DFT
FLUOROCARBENIUM ION
THIIRANIUM ION
THIOCARBENIUM ION
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:11336/2266
Acceder
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oai_identifier_str oai:ri.conicet.gov.ar:11336/2266
network_acronym_str CONICETDig
repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling α-Sulfur or α-fluorine - Which is more stabilizing for a carbocation? A computational study of electrophilic addition to HFCCH(SMe) and FC(R1)CR2(SMe) and related model systemsLaali, Kenneth K.Borosky, Gabriela LeonorΑ-F VERSUS Α-SMECHARGE DELOCALIZATIONDFTFLUOROCARBENIUM IONTHIIRANIUM IONTHIOCARBENIUM IONhttps://purl.org/becyt/ford/1.4https://purl.org/becyt/ford/1Carbocations derived from protonation, methylation, and bromine addition to HFC55CH(SMe) (1) were studied by DFT [B3LYP/6-31G*, B3LYP/6-311G(3df,p), and B3LYP/aug-cc-pVTZ] and by MP2/6-31G* to examine relative carbocation stabilizing effects of a-SMe versus a-fluorine. The a-SMe carbocations 1aE+ and the unsymmetrical thiiranium ions 1cE+ were found to be considerably more stable than the corresponding a-fluorocarbenium ions 1bE+ . Study of protonation and methylation of FC(R1)55CR2(SMe) [R1 = H, R2 = SMe (2); R1 = F, R2 = H (3); R1 = F, R2 = SMe (4); R1 = Me, R2 = H (5); R1 = Me, R2 = SMe (6)] by B3LYP/6-31G* identified the corresponding unsymmetrical thiiranium cations as lowest energy minima, followed closely by the a-thiocarbenium ions. With 2, 4, and 6, skeletally rearranged a-thiocarbenium ions are formed by SMe migration. The a-SMe and the thiiranium cations are also favored relative to a- fluorocarbenium ions in protonation and methylation of the cyclic analogs 8 and 9. Computed NPA charges and the GIAO-derived 13C and 19F NMR chemical shifts underscore the significance of athiocarbocations and thiiranium ions in electrophilic addition to FC(R1)55CR2(SMe).Fil: Laali, Kenneth K.. University of Florida; Estados UnidosFil: Borosky, Gabriela Leonor. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto de Investigaciones en Físicoquímica de Córdoba; ArgentinaElsevier Science SA2013-07info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/2266Laali, Kenneth K.; Borosky, Gabriela Leonor; α-Sulfur or α-fluorine - Which is more stabilizing for a carbocation? A computational study of electrophilic addition to HFCCH(SMe) and FC(R1)CR2(SMe) and related model systems; Elsevier Science SA; Journal of Fluorine Chemistry; 151; 7-2013; 26-310022-1139enginfo:eu-repo/semantics/altIdentifier/url/http://www.sciencedirect.com/science/article/pii/S0022113913001504info:eu-repo/semantics/altIdentifier/doi/10.1016/j.jfluchem.2013.04.003info:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-nd/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-12-03T08:34:26Zoai:ri.conicet.gov.ar:11336/2266instacron: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:34982025-12-03 08:34:26.926CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv α-Sulfur or α-fluorine - Which is more stabilizing for a carbocation? A computational study of electrophilic addition to HFCCH(SMe) and FC(R1)CR2(SMe) and related model systems
title α-Sulfur or α-fluorine - Which is more stabilizing for a carbocation? A computational study of electrophilic addition to HFCCH(SMe) and FC(R1)CR2(SMe) and related model systems
spellingShingle α-Sulfur or α-fluorine - Which is more stabilizing for a carbocation? A computational study of electrophilic addition to HFCCH(SMe) and FC(R1)CR2(SMe) and related model systems
Laali, Kenneth K.
Α-F VERSUS Α-SME
CHARGE DELOCALIZATION
DFT
FLUOROCARBENIUM ION
THIIRANIUM ION
THIOCARBENIUM ION
title_short α-Sulfur or α-fluorine - Which is more stabilizing for a carbocation? A computational study of electrophilic addition to HFCCH(SMe) and FC(R1)CR2(SMe) and related model systems
title_full α-Sulfur or α-fluorine - Which is more stabilizing for a carbocation? A computational study of electrophilic addition to HFCCH(SMe) and FC(R1)CR2(SMe) and related model systems
title_fullStr α-Sulfur or α-fluorine - Which is more stabilizing for a carbocation? A computational study of electrophilic addition to HFCCH(SMe) and FC(R1)CR2(SMe) and related model systems
title_full_unstemmed α-Sulfur or α-fluorine - Which is more stabilizing for a carbocation? A computational study of electrophilic addition to HFCCH(SMe) and FC(R1)CR2(SMe) and related model systems
title_sort α-Sulfur or α-fluorine - Which is more stabilizing for a carbocation? A computational study of electrophilic addition to HFCCH(SMe) and FC(R1)CR2(SMe) and related model systems
dc.creator.none.fl_str_mv Laali, Kenneth K.
Borosky, Gabriela Leonor
author Laali, Kenneth K.
author_facet Laali, Kenneth K.
Borosky, Gabriela Leonor
author_role author
author2 Borosky, Gabriela Leonor
author2_role author
dc.subject.none.fl_str_mv Α-F VERSUS Α-SME
CHARGE DELOCALIZATION
DFT
FLUOROCARBENIUM ION
THIIRANIUM ION
THIOCARBENIUM ION
topic Α-F VERSUS Α-SME
CHARGE DELOCALIZATION
DFT
FLUOROCARBENIUM ION
THIIRANIUM ION
THIOCARBENIUM ION
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.4
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv Carbocations derived from protonation, methylation, and bromine addition to HFC55CH(SMe) (1) were studied by DFT [B3LYP/6-31G*, B3LYP/6-311G(3df,p), and B3LYP/aug-cc-pVTZ] and by MP2/6-31G* to examine relative carbocation stabilizing effects of a-SMe versus a-fluorine. The a-SMe carbocations 1aE+ and the unsymmetrical thiiranium ions 1cE+ were found to be considerably more stable than the corresponding a-fluorocarbenium ions 1bE+ . Study of protonation and methylation of FC(R1)55CR2(SMe) [R1 = H, R2 = SMe (2); R1 = F, R2 = H (3); R1 = F, R2 = SMe (4); R1 = Me, R2 = H (5); R1 = Me, R2 = SMe (6)] by B3LYP/6-31G* identified the corresponding unsymmetrical thiiranium cations as lowest energy minima, followed closely by the a-thiocarbenium ions. With 2, 4, and 6, skeletally rearranged a-thiocarbenium ions are formed by SMe migration. The a-SMe and the thiiranium cations are also favored relative to a- fluorocarbenium ions in protonation and methylation of the cyclic analogs 8 and 9. Computed NPA charges and the GIAO-derived 13C and 19F NMR chemical shifts underscore the significance of athiocarbocations and thiiranium ions in electrophilic addition to FC(R1)55CR2(SMe).
Fil: Laali, Kenneth K.. University of Florida; Estados Unidos
Fil: Borosky, Gabriela Leonor. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto de Investigaciones en Físicoquímica de Córdoba; Argentina
description Carbocations derived from protonation, methylation, and bromine addition to HFC55CH(SMe) (1) were studied by DFT [B3LYP/6-31G*, B3LYP/6-311G(3df,p), and B3LYP/aug-cc-pVTZ] and by MP2/6-31G* to examine relative carbocation stabilizing effects of a-SMe versus a-fluorine. The a-SMe carbocations 1aE+ and the unsymmetrical thiiranium ions 1cE+ were found to be considerably more stable than the corresponding a-fluorocarbenium ions 1bE+ . Study of protonation and methylation of FC(R1)55CR2(SMe) [R1 = H, R2 = SMe (2); R1 = F, R2 = H (3); R1 = F, R2 = SMe (4); R1 = Me, R2 = H (5); R1 = Me, R2 = SMe (6)] by B3LYP/6-31G* identified the corresponding unsymmetrical thiiranium cations as lowest energy minima, followed closely by the a-thiocarbenium ions. With 2, 4, and 6, skeletally rearranged a-thiocarbenium ions are formed by SMe migration. The a-SMe and the thiiranium cations are also favored relative to a- fluorocarbenium ions in protonation and methylation of the cyclic analogs 8 and 9. Computed NPA charges and the GIAO-derived 13C and 19F NMR chemical shifts underscore the significance of athiocarbocations and thiiranium ions in electrophilic addition to FC(R1)55CR2(SMe).
publishDate 2013
dc.date.none.fl_str_mv 2013-07
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/11336/2266
Laali, Kenneth K.; Borosky, Gabriela Leonor; α-Sulfur or α-fluorine - Which is more stabilizing for a carbocation? A computational study of electrophilic addition to HFCCH(SMe) and FC(R1)CR2(SMe) and related model systems; Elsevier Science SA; Journal of Fluorine Chemistry; 151; 7-2013; 26-31
0022-1139
url http://hdl.handle.net/11336/2266
identifier_str_mv Laali, Kenneth K.; Borosky, Gabriela Leonor; α-Sulfur or α-fluorine - Which is more stabilizing for a carbocation? A computational study of electrophilic addition to HFCCH(SMe) and FC(R1)CR2(SMe) and related model systems; Elsevier Science SA; Journal of Fluorine Chemistry; 151; 7-2013; 26-31
0022-1139
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/url/http://www.sciencedirect.com/science/article/pii/S0022113913001504
info:eu-repo/semantics/altIdentifier/doi/10.1016/j.jfluchem.2013.04.003
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
dc.publisher.none.fl_str_mv Elsevier Science SA
publisher.none.fl_str_mv Elsevier Science SA
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 13.214268

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