Abstract
Dimethyl or diphenyl branched conjugated polycarbosilane oligomers in solutions, including poly[[1,4-bis(thiophenyl)buta-1, 3-diyne]-alt-(dimethylsilane)], poly-[[1,4-bis(thiophenyl)buta-1,3-diyne]-alt- (diphenylsilane)], poly[[1,4-bis(phenyl)buta-1, 3-diyne]-alt-(dimethylsilane)], and poly[[1,4-bis(phenyl)buta-1,3-diyne]-alt- (diphenylsilane)], were investigated by steady-state and picosecond time-resolved spectroscopies to elucidate the effect of silicon-atom introduction into the π-conjugated copolymer backbone and the substitution of the aromatic phenyl group on the silicon atom. The introduction of silicon atoms into π-conjugated copolymer backbones induces slow decay emission components with lifetimes of about 450 ps in addition to π-π* local excited-state relaxations in the time-resolved fluorescence decay profiles. The diphenyls, which are branched in the silicon atoms, bring about broad, structureless emission bands in the low-frequency region of the steady-state fluorescence spectra. However, such broad bands do not occur in the case of dimethyl branched conjugated polycarbosilane oligomers. The time-resolved and solvent-dependent studies of these bands imply that the excited-state dynamics of diphenyl branched conjugated polycarbosilane oligomers can be related to an intramolecular charge-transfer dynamics through an inductive and (d-p) π-conjugation effect between the π-conjugated backbone and the branched phenyl ring.
| Original language | English |
|---|---|
| Pages (from-to) | 2901-2908 |
| Number of pages | 8 |
| Journal | Journal of Polymer Science, Part B: Polymer Physics |
| Volume | 37 |
| Issue number | 20 |
| DOIs | |
| Publication status | Published - 1999 Oct 15 |
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All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Physical and Theoretical Chemistry
- Polymers and Plastics
- Materials Chemistry
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Excited-state dynamics of conjugated polycarbosilane oligomers with branched dimethyl or diphenyl group. / Hwang, I. W.; Song, N. W.; Kim, Dongho; Park, Y. T.; Kim, Yong Rok.
In: Journal of Polymer Science, Part B: Polymer Physics, Vol. 37, No. 20, 15.10.1999, p. 2901-2908.Research output: Contribution to journal › Article
TY - JOUR
T1 - Excited-state dynamics of conjugated polycarbosilane oligomers with branched dimethyl or diphenyl group
AU - Hwang, I. W.
AU - Song, N. W.
AU - Kim, Dongho
AU - Park, Y. T.
AU - Kim, Yong Rok
PY - 1999/10/15
Y1 - 1999/10/15
N2 - Dimethyl or diphenyl branched conjugated polycarbosilane oligomers in solutions, including poly[[1,4-bis(thiophenyl)buta-1, 3-diyne]-alt-(dimethylsilane)], poly-[[1,4-bis(thiophenyl)buta-1,3-diyne]-alt- (diphenylsilane)], poly[[1,4-bis(phenyl)buta-1, 3-diyne]-alt-(dimethylsilane)], and poly[[1,4-bis(phenyl)buta-1,3-diyne]-alt- (diphenylsilane)], were investigated by steady-state and picosecond time-resolved spectroscopies to elucidate the effect of silicon-atom introduction into the π-conjugated copolymer backbone and the substitution of the aromatic phenyl group on the silicon atom. The introduction of silicon atoms into π-conjugated copolymer backbones induces slow decay emission components with lifetimes of about 450 ps in addition to π-π* local excited-state relaxations in the time-resolved fluorescence decay profiles. The diphenyls, which are branched in the silicon atoms, bring about broad, structureless emission bands in the low-frequency region of the steady-state fluorescence spectra. However, such broad bands do not occur in the case of dimethyl branched conjugated polycarbosilane oligomers. The time-resolved and solvent-dependent studies of these bands imply that the excited-state dynamics of diphenyl branched conjugated polycarbosilane oligomers can be related to an intramolecular charge-transfer dynamics through an inductive and (d-p) π-conjugation effect between the π-conjugated backbone and the branched phenyl ring.
AB - Dimethyl or diphenyl branched conjugated polycarbosilane oligomers in solutions, including poly[[1,4-bis(thiophenyl)buta-1, 3-diyne]-alt-(dimethylsilane)], poly-[[1,4-bis(thiophenyl)buta-1,3-diyne]-alt- (diphenylsilane)], poly[[1,4-bis(phenyl)buta-1, 3-diyne]-alt-(dimethylsilane)], and poly[[1,4-bis(phenyl)buta-1,3-diyne]-alt- (diphenylsilane)], were investigated by steady-state and picosecond time-resolved spectroscopies to elucidate the effect of silicon-atom introduction into the π-conjugated copolymer backbone and the substitution of the aromatic phenyl group on the silicon atom. The introduction of silicon atoms into π-conjugated copolymer backbones induces slow decay emission components with lifetimes of about 450 ps in addition to π-π* local excited-state relaxations in the time-resolved fluorescence decay profiles. The diphenyls, which are branched in the silicon atoms, bring about broad, structureless emission bands in the low-frequency region of the steady-state fluorescence spectra. However, such broad bands do not occur in the case of dimethyl branched conjugated polycarbosilane oligomers. The time-resolved and solvent-dependent studies of these bands imply that the excited-state dynamics of diphenyl branched conjugated polycarbosilane oligomers can be related to an intramolecular charge-transfer dynamics through an inductive and (d-p) π-conjugation effect between the π-conjugated backbone and the branched phenyl ring.
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U2 - 10.1002/(SICI)1099-0488(19991015)37:20<2901::AID-POLB10>3.0.CO;2-4
DO - 10.1002/(SICI)1099-0488(19991015)37:20<2901::AID-POLB10>3.0.CO;2-4
M3 - Article
VL - 37
SP - 2901
EP - 2908
JO - Journal of Polymer Science, Part B: Polymer Physics
JF - Journal of Polymer Science, Part B: Polymer Physics
SN - 0887-6266
IS - 20
ER -