2005 Fiscal Year Final Research Report Summary
Synthesis and Photo Electronic Properties of Novel π-Stacked Polymers
| Project/Area Number |
16550110
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Polymer chemistry
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| Research Institution | Nara Institute of Science and Technology |
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Principal Investigator |
NAKANO Tamaki Nara Institute of Science and Technology, Graduate School of Materials Science, Associate Professor, 物質創成科学研究科, 助教授 (40227856)
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| Project Period (FY) |
2004 – 2005
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| Keywords | conductive polymers / π-electronic materials / oxidation / electron spin resonance spectrum / near infra red absorption spectrum / charge transfer / radical cation / olieomers |
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| Research Abstract |
We found that free-radical polymerization under appropriate conditions can give polydibenzofulvene having a π-stacked conformation as well as anionic polymerization. The free-radical polymerization product contained a small amount of defective conformation incorporated in the chain. Such a partial conformational defect was revealed to contribute to increase solubility of the polymer. In addition, as a new bulky dibenzofulvene derivative, 2,7-di-t-butyldibenzofulvene, was synthesized and polymerized in order to examine the effect of the side chain on polymerizability of the monomer and properties of the polymerization product. The bulky new monomer showed relatively low reactivity in anionic polymerization and led to oligomers mainly up to trimer. Photophysical properties of the obtained oligomers shed light on how unsubstituted polydibenzofulvene shows hypochromicity in absorption spectra and excimer emission in fluorescence spectra. Furthermore, absorption spectra of a radical cation species of oligo- and polydibenzofulvene generated by their chemical oxidation were measured in order to obtain information on charge transport properties. The radical cation species indicated a clear charge transfer band in near IR region, supporting the proposed charge transport through the stacked fluorene rings. In addition to the above investigations on polydibenzofulvene, poly(9-fluorenyl methacrylate) having various tacticity was synthesized by stereospecific anionic polymerization technique and the structure and the properties of the polymers were examined. The aim of this investigation was to find a new π-stacked polymer having a polymethacrylate backbone. Although the polymers were found not to have a stable π-stacked conformation in solution, they showed different photophysical properties depending on the main-chain tacticity.
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