Open AccessExcimer and Aggregate Formations in Poly(fluorene)s
Author(s) -
Lee JeongIk,
Lee Victor Y.,
Miller Robert D.
Publication year - 2002
Publication title -
etri journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.295
H-Index - 46
eISSN - 2233-7326
pISSN - 1225-6463
DOI - 10.4218/etrij.02.0102.0001
Subject(s) - fluorene , excimer , materials science , photochemistry , polymer , copolymer , absorption (acoustics) , polymerization , polymer chemistry , excited state , absorption band , ground state , fluorescence , chemistry , optics , composite material , atomic physics , physics
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.