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dc.date.accessioned | 2023-10-19T18:51:30Z | |
dc.date.available | 2023-10-19T18:51:30Z | |
dc.date.issued | 2003 | |
dc.identifier.uri | http://sedici.unlp.edu.ar/handle/10915/159129 | |
dc.description.abstract | The oxidation kinetics and mechanism of the phenolic derivatives of α,α,α-trifluorotoluene, 2-trifluoromethylphenol, 3-trifluoromethylphenol (3-TFMP), 4-trifluoromethylphenol and 3,5-bis(trifluoromethyl)phenol, mediated by singlet molecular oxygen, O2(¹Δg), and hydrogen phosphate radicals were studied, employing time-resolved O2(¹Δg) phosphorescence detection, polarographic determination of dissolved oxygen and flash photolysis. All the substrates are highly photo-oxidizable through a O2(¹Δg)-mediated mechanism. The phenols show overall quenching constants for O2(¹Δg) of the order of 106 M⁻¹ s⁻¹ in D2O, while the values for the phenoxide ions in water range from 1.2 × 10⁸ to 3.6 × 10⁸ M⁻¹ s⁻¹. The effects of the pH and polarity of the medium on the kinetics of the photo-oxidative process suggest a charge-transfer mechanism. 2-Trifluoromethyl-1,4-benzoquinone is suspected to be the main photo-oxidation product for the substrate 3-TFMP. The absolute rate constants for the reactions of HPO4•− with the substrates range from 4 × 10⁸ to 1 × 10⁹ M⁻¹ s⁻¹. The 3-trifluoromethylphenoxyl radical was observed as the organic intermediate formed after reaction of 3-TFMP with HPO₄•⁻, yielding 2,2’-bis(fluorohydroxymethyl)biphenyl-4,4’-diol as the end product. The observed results indicate that singlet molecular oxygen and hydrogen phosphate radicals not only react at different rates with the phenols of α,α,α-trifluorotoluene, but the reactions also proceed through different reaction channels. | en |
dc.format.extent | 882-887 | es |
dc.language | en | es |
dc.subject | phenolic derivatives | es |
dc.subject | oxidation kinetics | es |
dc.title | Kinetic study of the oxidation of phenolic derivatives of α,α,α-trifluorotoluene by singlet molecular oxygen [O₂(¹Δg)] and hydrogen phosphate radicals | en |
dc.type | Articulo | es |
sedici.identifier.other | https://doi.org/10.1039/b302502k | es |
sedici.identifier.issn | 1474-9092 | es |
sedici.creator.person | Rosso, Janina Alejandra | es |
sedici.creator.person | Criado, Susana | es |
sedici.creator.person | Bertolotti, Sonia G. | es |
sedici.creator.person | Allegretti, Patricia Ercilia | es |
sedici.creator.person | Furlong, Jorge Javier Pedro | es |
sedici.creator.person | García, Norman A. | es |
sedici.creator.person | González, Mónica Cristina | es |
sedici.creator.person | Mártire, Daniel Osvaldo | es |
sedici.subject.materias | Química | es |
sedici.description.fulltext | true | es |
mods.originInfo.place | Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas | es |
mods.originInfo.place | Laboratorio de Estudio de Compuestos Orgánicos | es |
sedici.subtype | Articulo | es |
sedici.rights.license | Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) | |
sedici.rights.uri | http://creativecommons.org/licenses/by-nc-sa/4.0/ | |
sedici.description.peerReview | peer-review | es |
sedici.relation.journalTitle | Photochemical & Photobiological Sciences | es |
sedici.relation.journalVolumeAndIssue | vol. 2, no. 8 | es |