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https://repositorio.ufba.br/handle/ri/15084
metadata.dc.type: | Artigo de Periódico |
Title: | Determinação da constante de velocidade absoluta para a reação de abstração de hidrogênio fenólico pelo estado excitado triplete de xantona em acetonitrila e no líquido iônico hexafluorfosfato de 1-butil-3-metil-imidazólio [bmim.PF6] |
Other Titles: | Química Nova |
Authors: | Bertoti, Ada Ruth Ferreira, José Carlos Netto |
metadata.dc.creator: | Bertoti, Ada Ruth Ferreira, José Carlos Netto |
Abstract: | The triplet excited state of xanthone was generated and characterized by laser flash photolysis in acetonitrile (λmax=620 nm; t=1.8 ms) and in ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate [bmim.PF6] (λmax=620 nm; t=3.0 ms). It reacts with phenols yielding the corresponding xanthone ketyl radical. Stern-Volmer plots for the reaction of triplet xanthone with phenols led to the determination of absolute rate constants for phenolic hydrogen abstraction in the order of ~109 Lmol-1s-1 in acetonitrile and ~108 Lmol-1s-1 in [bmim.PF6]. The lower diffusioncontrolled rate constant for [bmim.PF6] is responsible for the difference in the phenolic hydrogen abstraction rate constants in this solvent. |
Keywords: | Xanthone Ionic liquid Triplet excited state |
metadata.dc.publisher.country: | Brasil |
metadata.dc.rights: | Acesso Aberto |
URI: | http://repositorio.ufba.br/ri/handle/ri/15084 |
Issue Date: | 2013 |
Appears in Collections: | Artigo Publicado em Periódico (Química) |
Files in This Item:
File | Description | Size | Format | |
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0100-40422013000400008.pdf | 1,16 MB | Adobe PDF | View/Open |
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