Please use this identifier to cite or link to this item: https://repositorio.ufrn.br/jspui/handle/123456789/29213
Title: Topological study of the first step of nucleophilically unassisted solvolysis of protonated 2-endo/exo-norbornanol and protonated 2-endo/exo-oxabicycloheptanol
Authors: Firme, Caio Lima
Keywords: QTAIM;2-norbornyl cation;Sigma bond participation;2-oxabicycloheptanol;Solvolysis
Issue Date: Mar-2012
Publisher: Sociedade Brasileira de Química
Citation: FIRME, Caio Lima. Topological study of the first step of nucleophilically unassisted solvolysis of protonated 2-endo/exo-norbornanol and protonated 2-endo/exo-oxabicycloheptanol. Journal Of The Brazilian Chemical Society, [s. l.], v. 23, n. 3, p. 513-521, mar. 2012. ISSN 0103-5053. DOI https://doi.org/10.1590/S0103-50532012000300019. Disponível em: https://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532012000300019. Acesso em: 09 jun. 2020.
Portuguese Abstract: The assistance of s electron delocalization or anchimeric assistance of s electrons accounts for the large rate differences in the solvolysis of 2-exo- and 2-endo-norbornyl-p-bromobenzenesulfonates. This study was formerly analyzed by molecular orbital theory in gas phase. By revisiting this old problem from the quantum theory of atoms in molecules (QTAIM), new information on these reactions was obtained. The QTAIM results show that, in the first step of the nucleophilically unassisted solvolysis of protonated 2-exo-norbornanol and of protonated 2-endo-norbornanol, both reactions are anchimerically assisted by sigma bond participation. Similarly, in the first step of the nucleophilically unassisted solvolysis of protonated 2-endo-oxabicycloheptanol and of protonated 2-exo-oxabicycloheptanol, the QTAIM results show that both reactions are anchimerically assisted: the former from sigma bond participation from O-C bonds and valence shell electron participation from oxygen atom and the latter from sigma bond participation from C1-C2 bond.
Abstract: A assistência da deslocalização de elétrons sigma ou assistência anquimérica dos elétrons sigma explica grandes diferenças de velocidade na solvólise de 2-exo- e 2-endo-norbornil-p-bromobenzenosulfonatos. Este estudo foi anteriormente analisado pela teoria dos orbitais moleculares em fase gás. Ao revisitar este antigo problema a partir da teoria quântica de átomos em moléculas (QTAIM), novas informações sobre essas reações foram obtidas. Os resultados de QTAIM mostram que, na primeira etapa da solvólise não assistida nucleofilicamente dos alcoóis protonados 2-exo-norbornanol e 2-endo-norbornanol, ambas as reações são anquimericamente assistidas pela participação de elétrons sigma. Similarmente, na primeira etapa da solvólise não assistida nucleofilicamente dos álcoois protonados 2-endo-oxabicicloheptanol e 2-exo-oxabicicloheptanol, os resultados de QTAIM mostram que ambas as reações são anquimericamente assistidas: a primeira a partir da participação da ligação sigma C-O e de pares de elétrons isolados do oxigênio e a última a partir da participação da ligação sigma C1-C2.
URI: https://repositorio.ufrn.br/jspui/handle/123456789/29213
ISSN: 0103-5053 (print), 1678-4790 (online)
Appears in Collections:IQ - Artigos publicados em periódicos

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