| Project/Area Number |
07651114
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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 |
高分子構造・物性(含繊維)
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| Research Institution | Oita University |
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Principal Investigator |
EGASHIRA Naoyoshi Oita University, Faculty of Engineering, Associate Professor, 工学部, 助教授 (90094060)
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| Project Period (FY) |
1995 – 1996
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| Project Status |
Completed (Fiscal Year 1996)
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| Budget Amount *help |
¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1996: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 1995: ¥600,000 (Direct Cost: ¥600,000)
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| Keywords | Modified cyclodextrin / Inclusion complex / Molecular assembly / Electric stimulus / viologen moiety / nicotinamide moiety / Control / 修飾シクロデキストリン / 分子集合状態の制御 / ビオローゲン部位 / ニコチンアミド部位 / 機能性分子 / アゾベンゼン構造 / ニコチンアミド構造 |
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| Research Abstract |
We prepared novel beta-cyclodextrins (1 and 2) modified with viologen and nicotinamide moieties which were bind through a long alkyl chain (n=10), respectively. The cyclodextrins were purified by liquid chromatography and identified by NMR.
^1H NMR and NOE (D_2O) strongly suggested that the methylene moiety of 1 was included in the CD cavity. Two-step reversible waves were observed in the cyclic voltammogram. Interestingly, the current of the first reduction wave was almost 30% of that of the second one which was 70% of the current expected from a reversible one electron transfer. The small currents of 1 may be due to formation of a super molecular, a kind of oligomer, through intermolecular inclusion which leads to an decrease in the diffusion coefficient. The large difference between the first and second currents can be also explained by formation of more highly stable inclusion complex for 2^+. An increase in viscosity of an aqueous solution of 1 strongly suggested formation of the oligomer. The controlled-potential electrolysis at the second wave led to an decrease in viscosity, the viscosity change is reversible.
For 2, the formation of a stable inclusion complex was also confirmed by NMR.A weak inductive circular dichlonism spectrum due to the nicotinamide moiety suggested the existence in the neighborhood of nhe limb of the cyclodextrin cavity The experiment for the electric stimulus was not performed because the cathodic wave was irreversible.
In conclusion, both cyclodextrin derivatives formed highly stable inclusion complexes and the change in an intermolecular inclusion complex of 1 by electric stimulus was observed as we had expected. We are studying a cyclodextrin derivative designed so as to show a large change in viscosity by electric stimulus.
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