Conjugation Length Dependence of Intramolecular Singlet Fission in a Series of Regioregular Oligo 3-Alkyl(thienylene-vinylene)s
Year: 2024
Type: article
Abstract: High Resolution Image Download MS PowerPoint Slide Activated intramolecular singlet fission is known to occur in the conjugated polymer polythienylene-vinylene (P3TV). Instead, efficient intersystem crossing has been observed in a short 3-alkyl(thienylene-vinylene) dimer. Here, we investigate a series of oligomers covering the conjugation length gap between the dimer and polymer. We confirm that the polymer and longer oligomers undergo activated intramolecular singlet fission, while the shorter oligomers with less than 3 units predominantly undergo efficient intersystem crossing. For the longer oligomers, the intermediate state of singlet fission is assigned to the 3A g – covalent state of triplet pair character, as predicted by several computational studies. Our results point to potential pitfalls when assigning triplet production pathways solely with transient absorption spectroscopy.
DOI: 10.1021/jacs.4c12877
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,500
Awards: Maximising Shared Capability of the Ultrafast Spectroscopy Laser Laboratory at Sheffield, G2982831656, G3071847351, EPSRC Centre for Doctoral Training in Plastic Electronic Materials, Capability for Science of the Future: Ultrafast Spectroscopy Laser Centre at Sheffield, USLS, Singlet Fission in Carotenoid Aggregates (SIFICA), G671760286, G6933235266, Singlet fission in polyenes, G744483401, Hybrid Polaritonics, G8053759440
OpenAlex ID: W4405720294