Abstract
The dynamics of intramolecular excimer formation in isotactic (mm), syndiotactic (rr), and heterotactic (mr) 4,6,8-triphenylundecanes (PS3), which are diastereomeric trimer model compounds of polystyrene, were investigated by picosecond pulse radiolysis. The monomeric fluorescence of rr PS3 decays single exponentially with a time constant of 7.4 ns, while those of mm PS3 and mr PS3 decay dual exponentially with time constants of approximately 0.5 and 4 ns. The multicomponent fluorescence decays are influenced by local molecular motion (conformational change). The results suggest that the phenyl groups do not rotate independently around the carbon-carbon bonds of the backbone but that their rotation involves a cooperative motion of backbone chain bonds. The existence of singlet energy migration is established by the fact that the monomeric fluorescence decay curve of mr PS3 does not have as long a decay constant as the curves of the racemic isomers r PS2 and rr PS3 have.
| Original language | English |
|---|---|
| Pages (from-to) | 2520-2525 |
| Number of pages | 6 |
| Journal | Macromolecules |
| Volume | 22 |
| Issue number | 5 |
| Publication status | Published - 1989 May |
| Externally published | Yes |
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ASJC Scopus subject areas
- Materials Chemistry
Cite this
Local molecular motion of polystyrene model compounds measured by picosecond pulse radiolysis. 2. Multicomponent fluorescence decay curves of diastereomeric styrene trimers. / Itagaki, Hideyuki; Horie, Kazuyuki; Mita, Itaru; Washio, Masakazu; Tagawa, Seiichi; Tabata, Yoneho; Sato, Hisaya; Tanaka, Yasuyuki.
In: Macromolecules, Vol. 22, No. 5, 05.1989, p. 2520-2525.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Local molecular motion of polystyrene model compounds measured by picosecond pulse radiolysis. 2. Multicomponent fluorescence decay curves of diastereomeric styrene trimers
AU - Itagaki, Hideyuki
AU - Horie, Kazuyuki
AU - Mita, Itaru
AU - Washio, Masakazu
AU - Tagawa, Seiichi
AU - Tabata, Yoneho
AU - Sato, Hisaya
AU - Tanaka, Yasuyuki
PY - 1989/5
Y1 - 1989/5
N2 - The dynamics of intramolecular excimer formation in isotactic (mm), syndiotactic (rr), and heterotactic (mr) 4,6,8-triphenylundecanes (PS3), which are diastereomeric trimer model compounds of polystyrene, were investigated by picosecond pulse radiolysis. The monomeric fluorescence of rr PS3 decays single exponentially with a time constant of 7.4 ns, while those of mm PS3 and mr PS3 decay dual exponentially with time constants of approximately 0.5 and 4 ns. The multicomponent fluorescence decays are influenced by local molecular motion (conformational change). The results suggest that the phenyl groups do not rotate independently around the carbon-carbon bonds of the backbone but that their rotation involves a cooperative motion of backbone chain bonds. The existence of singlet energy migration is established by the fact that the monomeric fluorescence decay curve of mr PS3 does not have as long a decay constant as the curves of the racemic isomers r PS2 and rr PS3 have.
AB - The dynamics of intramolecular excimer formation in isotactic (mm), syndiotactic (rr), and heterotactic (mr) 4,6,8-triphenylundecanes (PS3), which are diastereomeric trimer model compounds of polystyrene, were investigated by picosecond pulse radiolysis. The monomeric fluorescence of rr PS3 decays single exponentially with a time constant of 7.4 ns, while those of mm PS3 and mr PS3 decay dual exponentially with time constants of approximately 0.5 and 4 ns. The multicomponent fluorescence decays are influenced by local molecular motion (conformational change). The results suggest that the phenyl groups do not rotate independently around the carbon-carbon bonds of the backbone but that their rotation involves a cooperative motion of backbone chain bonds. The existence of singlet energy migration is established by the fact that the monomeric fluorescence decay curve of mr PS3 does not have as long a decay constant as the curves of the racemic isomers r PS2 and rr PS3 have.
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M3 - Article
VL - 22
SP - 2520
EP - 2525
JO - Macromolecules
JF - Macromolecules
SN - 0024-9297
IS - 5
ER -