BIBLIOS

Tipo
Artigos em Revista

Tipo de Documento
Artigo Completo

Título
Solvation Effects in the Heterolyses of 3-X-3- Methylpentanes (X=Cl, Br, I)

Participantes na publicação
F. Martins (Author)
Dep. Química e Bioquímica
CQB
R. E. Leitão (Author)
L. Moreira. (Author)

Resumo
A comparative study of the heterolysis reactions of 3?X?3?methylpentanes (X = Cl, Br, I) in a set of protic and aprotic solvents was performed at 25.00°C. Rate constant values were correlated with solvent descriptors using the TAKA multiparametric equation. Our results point towards a decrease in both hydrogen bond donor acidity (electrophilicity) and hydrogen bond acceptor basicity (nucleophilicity) contributions, and towards an increase in the dipolarity/polarizability term on going from the chloride substrate to iodide. These features suggest the formation of an increasingly early transition state, in contrast to the classical Hughes–Ingold rationale, but in agreement with the Hammond postulate. Furthermore, there seems to be no evidence for a shift in solvation from an electrophilic (or anionic) mode in the chloride substrate to a nucleophilic (or cationic) mode in the iodide, as claimed by some authors. Copyright © 2004 John Wiley & Sons, Ltd.


Instituição
FACULDADE DE CIÊNCIAS DA UNIVERSIDADE DE LISBOA

Suporte
JOURNAL OF PHYSICAL ORGANIC CHEMISTRY

Identificadores da Publicação
ISSN - 0894-3230

Editora
John Wiley & Sons, Ltd.



Identificadores do Documento
DOI - https://doi.org/10.1002/poc.816

Identificadores de Qualidade
SCIMAGO Q3 (2004) - 0.608 - Physical and Theoretical Chemistry
Web Of Science Q3 (2006) - 1.211 - Chemistry, Physical

Keywords
Reaction kinetics 3-Halo-3-methylpentane Solute–solvent interactions Linear solvation energy relationships