Please use this identifier to cite or link to this item: https://hdl.handle.net/10316/10453
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dc.contributor.authorDias, Fernando B.-
dc.contributor.authorKnaapila, Matti-
dc.contributor.authorMonkman, Andrew P.-
dc.contributor.authorBurrows, Hugh D.-
dc.date.accessioned2009-07-02T08:51:22Z-
dc.date.available2009-07-02T08:51:22Z-
dc.date.issued2006-02-21-
dc.identifier.citationMacromolecules. 39:4 (2006) 1598-1606en_US
dc.identifier.issn0024-9297-
dc.identifier.urihttps://hdl.handle.net/10316/10453-
dc.description.abstractThe luminescence decay kinetics of polyfluorene copolymers containing fluorenone units randomly distributed along the polymer chain have been studied by steady-state and time-resolved fluorescence techniques in toluene solution. The typical green emission from polyfluorenes containing 9-fluorenone moieties is only observed if the 9-fluorenone group is covalently attached to the polymer. Small-angle neutron scattering (SANS) measurements indicate that, independent of the 9-fluorenone fraction, all the studied copolymers adopt an open wormlike conformation. This prevalent 1-dimensional arrangement confirms that the green emission observed with polyfluorenes is not the result of excimer formation in the typical sandwich-like conformation. Analysis of time-resolved fluorescence decays by the maximum entropy method (MEM) collected at the polyfluorene emission (415 nm) and by global analysis of decays collected at 415 and 580 nm (the 9-fluorenone defect emission wavelength) clearly indicates two different time regimes in the population of the fluorenone defect: one occurring in the time interval of 10 to 30 ps and a second one occurring in the time range from 70 to 200 ps. While the slower process shows a linear dependence with the 9-fluorenone fraction, compatible with a hopping migration process along the polymer chain, the faster process does not show such a dependence and instead suggests a short-range Dexter mechanism. These findings are in agreement with our previous work where the presence of a faster component was suggested.en_US
dc.language.isoengen_US
dc.publisherAmerican Chemical Societyen_US
dc.rightsopenAccesseng
dc.titleFast and Slow Time Regimes of Fluorescence Quenching in Conjugated Polyfluorene−Fluorenone Random Copolymers: The Role of Exciton Hopping and Dexter Transfer along the Polymer Backboneen_US
dc.typearticleen_US
dc.identifier.doi10.1021/ma052505l-
uc.controloAutoridadeSim-
item.fulltextCom Texto completo-
item.openairecristypehttp://purl.org/coar/resource_type/c_18cf-
item.grantfulltextopen-
item.languageiso639-1en-
item.openairetypearticle-
item.cerifentitytypePublications-
crisitem.author.researchunitCQC - Coimbra Chemistry Centre-
crisitem.author.parentresearchunitFaculty of Sciences and Technology-
crisitem.author.orcid0000-0002-4114-9798-
crisitem.author.orcid0000-0003-3127-2298-
Appears in Collections:FCTUC Química - Artigos em Revistas Internacionais
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