Triplet excimer formation of dibromocarbazole chromophores in methacrylate copolymer films measured by time-resolved phosphorescence and transient absorption spectroscopy

Journal Article · Thu Aug 04 04:00:00 EDT 1994 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100082a035· OSTI ID:7178390

Ito, Shinzaburo; Yamamoto, Masahide ^[1]; Liebe, W R; Burkhart, R D ^[2]; Wada, Yoshio ^[3]

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1. Kyoto Univ. (Japan)
2. Univ. of Nevada, Reno, NV (United States)
3. Kyoto Inst. of Technology (Japan)

Time-resolved phosphorescence and transient absorption spectroscopy have been carried out for studying the triplet states of the 3,6-dibromocarbazole (DBCz) chromophore in a solid matrix of methacrylate copolymer. poly[2-(3,6-dibromo-9-carbazoyl)ethyl methacrylate-co-methyl methacrylate]. The sample film containing 10% DBCz units showed critical behavior in the time-resolved phosphorescence spectra which altered the shape from the monomer state [sup 3]M* to two kinds of excimer states: E1 and E2 (460 and 510 nm at the maximum intensity, respectively). These excimeric species have identical profiles with those reported for poly(3,6-dibromo-9-vinylcarbazole), although the polymer structures are totally different. This result shows that the DBCz chromophores tend to take some preferential geometry which results in the formation of two distinct excimer sites in the polymer film. The spectral alteration with time was drastically accelerated by thermal activation in the temperature range 25-77 K. Iterative trapping and detrapping processes determine the rate of relaxation to the deeper traps, E1 and E2. 15 refs., 8 figs., 1 tab.

• DOE Contract Number: FG03-92ER45476
• OSTI ID: 7178390
• Journal Information: Journal of Physical Chemistry; (United States), Journal Name: Journal of Physical Chemistry; (United States) Vol. 98:31; ISSN JPCHAX; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400102 -- Chemical & Spectral Procedures
400201* -- Chemical & Physicochemical Properties
400500 -- Photochemistry
ABSORPTION SPECTROSCOPY
CHEMICAL REACTIONS
COPOLYMERS
ELECTRONIC STRUCTURE
ENERGY LEVELS
ESTERIFICATION
EXCIMER LASERS
EXCITED STATES
FILMS
GAS LASERS
LASERS
LUMINESCENCE
MULTIPLETS
ORGANIC COMPOUNDS
ORGANIC POLYMERS
PHOSPHORESCENCE
POLYMERS
SPECTROSCOPY
TRAPPING
TRIPLETS