| Project/Area Number |
10450359
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
高分子構造・物性(含繊維)
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| Research Institution | University of Tsukuba |
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Principal Investigator |
SHIRAKAWA Hideki University of Tsukuba, Institute of Materials Science, Professor, 物質工学系, 教授 (40016720)
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| Co-Investigator(Kenkyū-buntansha) |
AKAGI Kazuo University of Tsukuba, Institute of Materials Science, Professor, 物質工学系, 教授 (20150964)
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| Project Period (FY) |
1998 – 1999
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| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 1999: ¥3,000,000 (Direct Cost: ¥3,000,000)
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| Keywords | Polyacetylene / Helical structure / Chiral nematic liquid crystal / Chiral dopant / Asymmetric reaction field / Electrical conductivity / Vertically aligned fibrils / Molecular solenoid / 導電性高分子 / ヘリカル構造 / 光学活性 / 不斉異方性反応場 / 分子素子 / カイラルネマティック液晶 |
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| Research Abstract |
Helical polyacetylene recently developed is anticipated to show novel electromagnetic and optical properties. Recently we synthesized for the first time helical polyacetylene films with left- and right-handed screw structures under chiral nematic reaction field. Here, we extended the synthesis of helical polyacetylene by developing the following approaches shown below.
(1) Novel chiral titanium complexes as chiral dopants with catalytic activity for synthesis of helical polyacetylene : We synthesized a series of chiral titanium complexes with chiral center-containing groups or axially chiral 1,1'-binaphthyl ones as coordination ligands, to develop catalytically active chiral dopants feasible for the asymmetric polymerization of acetylene. It is found that these complexes induce chiral nematic (N^*) phase when dissolved in a mixture of two nematic liquid crystals (LCs) and can polymerize acetylene to give helical polyacetylene with an aid of Et_3Al used as a co-catalyst under the N^* LC.
(2) Synthesis of Vertically Aligned Helical Polyacetylene Films in Homeotropic Chiral Nematic Liquid Crystals : We constructed a novel homeotropic N^* LC reaction field for synthesis of vertically aligned helical PA film. The homeotropic N^* LC was prepared by adding chiral dopant, (R)- or (S)-PCH506-binol and (R)- or (S)-PCH308^* into the homeotropic nematic LCs consisting of PCH506 + (PCH30))_26, PCH506 + (PCH50))_26, and PCH506 + (PCH50)_28. Scanning electron microscope (SEM) measurements showed twisted polyacetylene fibrils are grown parallel to the direction of film thickness, giving vertically aligned helical fibrillar morphology.
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