Triplet-state and singlet oxygen formation in fluorene-based alternating copolymers

The Journal of Physical Chemistry. B
S M FonsecaS Navaratnam

Abstract

Data are reported on the triplet states of a series of fluorene-based A-alt-B type alternating copolymers based on pulse radiolysis-energy transfer and flash photolysis experiments. From the pulse radiolysis experiments, spectra are given for eight copolymers involving phenylene, thiophene, benzothiadiazole, and oligothienylenevinylene groups. Quantum yields for triplet-state formation (PhiT) have been obtained by flash photolysis following laser excitation and in one case by photoacoustic calorimetry. In addition, yields of sensitized formation of singlet oxygen have been determined by time-resolved phosphorescence and are, in general, in excellent agreement with the PhiT values. In all cases, the presence of thiophene units is seen to increase intersystem-crossing quantum yields, probably because of the presence of the heavy sulfur atom. However, with the poly[2,7-(9,9-bis(2'-ethylhexyl)fluorene)-alt-1,4-phenylene] (PFP), thiophene S,S-dioxide (PFTSO2) and benzothiadiazole (F8BT) copolymers, low yields of triplet formation are observed. With three of the copolymers, the energies of the triplet states have been determined. With PFP, the triplet energy is virtually identical to that of poly[2,7-(9,9-bis(2'-ethylhexyl)fluorene)]...Continue Reading

References

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Citations

Oct 11, 2016·Photochemical & Photobiological Sciences : Official Journal of the European Photochemistry Association and the European Society for Photobiology·Tatsumoto NakahamaSeiya Kobatake
Sep 6, 2018·Photochemical & Photobiological Sciences : Official Journal of the European Photochemistry Association and the European Society for Photobiology·Farhan SadiqZhijia Wang
Feb 2, 2009·Advanced Materials·Robert AbbelAlbertus P H J Schenning
May 18, 2010·Photochemical & Photobiological Sciences : Official Journal of the European Photochemistry Association and the European Society for Photobiology·Hugh D BurrowsSuppiah Navaratnam
Jan 10, 2013·Dalton Transactions : an International Journal of Inorganic Chemistry·M Luísa RamosHugh D Burrows
Sep 8, 2012·Dalton Transactions : an International Journal of Inorganic Chemistry·M Luísa RamosHugh D Burrows
Apr 2, 2010·ACS Applied Materials & Interfaces·Hugh D BurrowsVasil M Garamus
Aug 4, 2006·The Journal of Physical Chemistry. B·J PinaU Scherf
Aug 19, 2007·The Journal of Physical Chemistry. a·Hsin-Liang ChenWunshain Fann
Aug 19, 2018·Biomedicine & Pharmacotherapy = Biomédecine & Pharmacothérapie·Stanisław KwiatkowskiJulita Kulbacka

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