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Detail
Journal Article
Excimer and Aggregate Formations in Poly(fluorene)s
- Authors
- Jeong-Ik Lee, Victor Y. Lee, Robert D. Miller
- Issue Date
- 2002-12
- Citation
- ETRI Journal, v.24, no.6, pp.409-414
- ISSN
- 1225-6463
- Publisher
- 한국전자통신연구원 (ETRI)
- Language
- English
- Type
- Journal Article
- Abstract
- This paper investigates the absorption and emission changes in poly(di-n-hexylfluorene)s. We prepared the poly(di-n-hexylfluorene)s end capped with 2-bromofluorene, 2-bromo-9,9-di-n-hexylfluorene, and 9-bromoanthracene through Ni (0) mediated polymerization. In addition, we also synthesized a structurally distorted copolymer of 2,7-dibromo-9,9-di-n-hexylfluorene and 9,9-bis(4-bromophenyl) fluorene end capped with 2-bromofluorene through the same polymerization method. The absorption and emission changes of these polymers between before and after thermal annealing in a nitrogen atmosphere clarify the role of aggregate/excimer formation in poly(fluorene)s. The large absorption changes must be attributed to aggregate formation (ground state interaction), which causes only a slight red shift of the vibronically structured emission bands. We assign the additional long wavelength emission as an excimer band (excited state interaction), which is preferably formed at chain ends.
- KSP Keywords
- 9-Bromoanthracene, Absorption and emission, Aggregate formation, Excimer formation, Nitrogen atmosphere, Polymerization method, Red-shift, Thermal annealing, excited state, ground state, long wavelength