Please use this identifier to cite or link to this item:
https://hdl.handle.net/10316/10453
DC Field | Value | Language |
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dc.contributor.author | Dias, Fernando B. | - |
dc.contributor.author | Knaapila, Matti | - |
dc.contributor.author | Monkman, Andrew P. | - |
dc.contributor.author | Burrows, Hugh D. | - |
dc.date.accessioned | 2009-07-02T08:51:22Z | - |
dc.date.available | 2009-07-02T08:51:22Z | - |
dc.date.issued | 2006-02-21 | - |
dc.identifier.citation | Macromolecules. 39:4 (2006) 1598-1606 | en_US |
dc.identifier.issn | 0024-9297 | - |
dc.identifier.uri | https://hdl.handle.net/10316/10453 | - |
dc.description.abstract | The 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.iso | eng | en_US |
dc.publisher | American Chemical Society | en_US |
dc.rights | openAccess | eng |
dc.title | Fast and Slow Time Regimes of Fluorescence Quenching in Conjugated Polyfluorene−Fluorenone Random Copolymers: The Role of Exciton Hopping and Dexter Transfer along the Polymer Backbone | en_US |
dc.type | article | en_US |
dc.identifier.doi | 10.1021/ma052505l | - |
uc.controloAutoridade | Sim | - |
item.fulltext | Com Texto completo | - |
item.openairecristype | http://purl.org/coar/resource_type/c_18cf | - |
item.cerifentitytype | Publications | - |
item.grantfulltext | open | - |
item.languageiso639-1 | en | - |
item.openairetype | article | - |
crisitem.author.researchunit | CQC - Coimbra Chemistry Centre | - |
crisitem.author.parentresearchunit | Faculty of Sciences and Technology | - |
crisitem.author.orcid | 0000-0002-4114-9798 | - |
crisitem.author.orcid | 0000-0003-3127-2298 | - |
Appears in Collections: | FCTUC Química - Artigos em Revistas Internacionais |
Files in This Item:
File | Description | Size | Format | |
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Fast and Slow Time Regimes of Fluorescence Quenching.pdf | 195.35 kB | Adobe PDF | View/Open |
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