Please use this identifier to cite or link to this item: https://repositorio.ufrn.br/jspui/handle/123456789/29209
Title: A combined laser flash photolysis, density functional theory and atoms in molecules study of the photochemical hydrogen abstraction by pyrene-4,5-dione
Authors: Lucas, Nanci Câmara de
Elias, Mônica Maciel
Firme, Caio Lima
Corrêa, Rodrigo José
Garden, Simon John
Netto-Ferreira, José Carlos
Nicodem, David Ernest
Keywords: Laser flash photolysis;Ortho-quinone;Triplet excited state;DFT;Hydrogen atom transfer
Issue Date: 1-Jan-2009
Publisher: Elsevier
Citation: LUCAS, Nanci Câmara de; ELIAS, Mônica Maciel; FIRME, Caio Lima; CORRÊA, Rodrigo José; GARDEN, Simon John; NETTO-FERREIRA, José Carlos; NICODEM, David Ernest. A combined laser flash photolysis, density functional theory and atoms in molecules study of the photochemical hydrogen abstraction by pyrene-4,5-dione. Journal Of Photochemistry And Photobiology A: Chemistry, [s. l.], v. 201, n. 1, p. 1-7, jan. 2009. ISSN 1010-6030. DOI https://doi.org/10.1016/j.jphotochem.2008.08.014. Disponível em: https://www.sciencedirect.com/science/article/abs/pii/S1010603008003791#!. Acesso em: 19 maio 2020.
Portuguese Abstract: The photochemical hydrogen abstraction reaction of pyrene-4,5-dione (3) has been investigated by laser flash photolysis. Excitation (λ = 355 nm) of a degassed solution of 3 in acetonitrile resulted in the formation of a detectable transient with absorption maxima at 380 and 470 nm. This transient decays with a lifetime of around 4.8 μs and is quenched by oxygen. This transient is most probably a triplet state of 3. Addition of hydrogen donors, such as 2-propanol; 1,4-cyclohexadiene or 4-methoxyphenol led to the formation of a new transient with λmax at 380, 500 nm and a broad absorption at 640 nm. This new transient slowly decays with second order kinetics and was assigned to the semiquinone radical obtained from the hydrogen abstraction reaction. Using DFT and AIM calculations the reactivity of 3 and 9,10-phenanthrenequinone (1) is best interpreted as a proton coupled electron transfer like mechanism for the hydrogen abstraction from 2-propanol.
URI: https://repositorio.ufrn.br/jspui/handle/123456789/29209
ISSN: 1010-6030
Appears in Collections:IQ - Artigos publicados em periódicos

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