| Project/Area Number |
05453033
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Organic chemistry
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| Research Institution | KYUSHU UNIVERSITY |
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Principal Investigator |
KOBAYASHI Shinjiro Kyushu Univ., Inst.Fund.Res.Org.Chem, Ass.Prof., 有機化学基礎研究センター, 助教授 (20037831)
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| Co-Investigator(Kenkyū-buntansha) |
TANIGUCHI Hiroshi Kyushu Univ., Fac.Eng., Prof., 工学部, 教授 (10037715)
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| Project Period (FY) |
1993 – 1994
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| Project Status |
Completed (Fiscal Year 1994)
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| Budget Amount *help |
¥6,700,000 (Direct Cost: ¥6,700,000)
Fiscal Year 1994: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 1993: ¥5,600,000 (Direct Cost: ¥5,600,000)
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| Keywords | vinyl cation / carbocation / resonance demand / substituent effect of beta-alkyl substituent / steric effect / solvent effect / solvolysis / photolysis / βアルキル基置換基効果 / betaアルキル基置換基効果 |
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| Research Abstract |
The purpose of this study is how a divalent vinyl cation is connected with trivalent carbocations and how characteristic a vinyl cation is.
1) Protonation to phenylacetylene derivatives in gas phase generates vinyl cations. The thermodynamics of various vinyl cations were evaluated with equation of linear relationship of aromatic substitution reaction. The r-values of b-substituted vinyl cations gave linear relationship with stability of the corresponding vinyl cations and also related with trivalent benzylic cations.
2) Solvent effect of solvolysis of vinyl derivatives were measured in aqueous ethanol. The problem of solubility was overcome with preparation of vinyl derivatives which have a hydrophilic ammmono group. Further investigation has to be done in extension.
3) A vinyl cation can be generated by laser flash photolysis of aryl-substituted vinyl halides. The behavior of a vinyl cation can be followed by measuring its decay rates under various solvolytic conditions. The nucleophilicity of solvent mixture is evaluated. There is large difference between beta-substituents of alpha-p-methoxyphenylvinyl cations due to steric repulsion between the beta-substituent and nucleophiles.
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