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RESEARCH PRODUCT
High Yield Ultrafast Intramolecular Singlet Exciton Fission in a Quinoidal Bithiophene
Juan AragóJuan T. López NavarreteOleg VarnavskiDavid CasanovaDavid CasanovaDavid CasanovaTheodore GoodsonKazuo TakimiyaNeranga AbeyasingheJuan José Serrano-pérezJuan CasadoEnrique Ortísubject
FissionChemistryQuantum yieldPhotochemistryPhotoexcitationCondensed Matter::Materials ScienceIntramolecular forceExcited stateSinglet fissionUltrafast laser spectroscopyFlash photolysisGeneral Materials SciencePhysics::Chemical PhysicsPhysical and Theoretical Chemistrydescription
We report the process of singlet exciton fission with high-yield upon photoexcitation of a quinoidal thiophene molecule. Efficient ultrafast triplet photogeneration and its yield are determined by photoinduced triplet-triplet absorption, flash photolysis triplet lifetime measurements, as well as by femtosecond time-resolved transient absorption and fluorescence methods. These experiments show that optically excited quinoidal bithiophene molecule undergoes ultrafast formation of the triplet-like state with the lifetime ∼57 μs. CASPT2 and RAS-SF calculations have been performed to support the experimental findings. To date, high singlet fission rates have been reported for crystalline and polycrystalline materials, whereas for covalently linked dimers and small oligomers it was found to be relatively small. In this contribution, we show an unprecedented quantum yield of intramolecular singlet exciton fission of ∼180% for a quinoidal bithiophene system.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2015-08-12 | The Journal of Physical Chemistry Letters |