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dc.contributor.authorBurrows, Hugh D
dc.contributor.authorNarwark, Oliver
dc.contributor.authorPeetz, Ralf
dc.contributor.authorThorn-Csányi, Emma
dc.contributor.authorMonkman, Andrew P
dc.contributor.authorHamblett, Ian
dc.contributor.authorNavaratnam, Suppiah
dc.date.accessioned2010-09-18T09:39:19Z
dc.date.available2010-09-18T09:39:19Z
dc.date.issued2010-07-30
dc.identifier.citationMechanistic studies on the photodegradation of 2,5-dialkyloxyl-substituted para-phenylenevinylene oligomers by singlet oxygen. 2010, 9 (7):942-8 Photochem. Photobiol Scien
dc.identifier.issn1474-9092
dc.identifier.pmid20473426
dc.identifier.doi10.1039/c0pp00053a
dc.identifier.urihttp://hdl.handle.net/10541/111355
dc.description.abstractTime-dependent UV/visible absorption changes are observed on photolysis of aerated solutions of monodisperse, vinyl end-capped 2,5-diheptyloxyl substituted PV-oligomers (OPV, n = 1, 2, 3). In all cases, photolysis occurs in at least two distinct stages. Evidence for the intermediacy of singlet oxygen comes from pulse radiolysis and time-resolved luminescence studies, which confirm formation of the OPV triplet state and its quenching by molecular oxygen to produce singlet oxygen. The subsequent reaction with oligomers is observed directly by time-resolved phosphorescence and indirectly through product identification. The results strongly suggest that the reaction between singlet oxygen and OPV proceeds via cycloaddition, leading to bond scission and aldehyde group formation. The reactivity of vinylene linkages is greater than of vinyl end groups. Consequently, the photostability decreases as the chain length is extended. Implications on the oxidative degradation of poly(p-phenylenevinylene)s in optoelectronic devices, and of competing singlet oxygen and superoxide radical anion degradation pathways, are discussed.
dc.language.isoenen
dc.subjectPhotolysisen
dc.subjectPulse Radiolysisen
dc.titleMechanistic studies on the photodegradation of 2,5-dialkyloxyl-substituted para-phenylenevinylene oligomers by singlet oxygen.en
dc.typeArticleen
dc.identifier.eissn1474-905X
dc.contributor.departmentDepartamento de Química, Universidade de Coimbra, 304-535, Coimbra, Portugal. burrows@ci.uc.pten
dc.identifier.journalPhotochemical & Photobiological Sciencesen
html.description.abstractTime-dependent UV/visible absorption changes are observed on photolysis of aerated solutions of monodisperse, vinyl end-capped 2,5-diheptyloxyl substituted PV-oligomers (OPV, n = 1, 2, 3). In all cases, photolysis occurs in at least two distinct stages. Evidence for the intermediacy of singlet oxygen comes from pulse radiolysis and time-resolved luminescence studies, which confirm formation of the OPV triplet state and its quenching by molecular oxygen to produce singlet oxygen. The subsequent reaction with oligomers is observed directly by time-resolved phosphorescence and indirectly through product identification. The results strongly suggest that the reaction between singlet oxygen and OPV proceeds via cycloaddition, leading to bond scission and aldehyde group formation. The reactivity of vinylene linkages is greater than of vinyl end groups. Consequently, the photostability decreases as the chain length is extended. Implications on the oxidative degradation of poly(p-phenylenevinylene)s in optoelectronic devices, and of competing singlet oxygen and superoxide radical anion degradation pathways, are discussed.


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