| Project/Area Number |
14550807
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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 |
有機工業化学
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| Research Institution | Kyoto University |
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Principal Investigator |
KITAGAWA Toshikazu Kyoto University, Institute for Chemical Research, Associate Professor, 化学研究所, 助教授 (20183791)
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| Co-Investigator(Kenkyū-buntansha) |
KOMATSU Koichi Kyoto University, Institute for Chemical Research, Professor, 化学研究所, 教授 (70026243)
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| Project Period (FY) |
2002 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥4,100,000 (Direct Cost: ¥4,100,000)
Fiscal Year 2003: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 2002: ¥2,600,000 (Direct Cost: ¥2,600,000)
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| Keywords | fullereneC60 / carbocation / solvolysis / pKR+ / electron transfer / silica / monolayer / surface coating / カルボカチオン塩 / 超強酸 / シリコンウエファー / フラーレン / カルボカオチン / pK_R^+ |
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| Research Abstract |
1.Quantitative Determination of the Thermodynamic Stabilities of Alkylfullerenyl Cations
The thermodynamic stabilities of alkylfullerenyl cations were evaluated by the kinetic measurements for the S_N1 solvolysis of chlorides R-C_<60>-Cl and by precise determination of the equilibrium constants of the ionization of fullerenols R-C_<60>-OH. The results of these experiments demonstrated that alkylfullerenyl cations have stabilities comparable to that of the tert-butyl cation.
2.Preparation of Alkylfullerenyl Cation as Long-lived Species in Solution and Its Isolation as a Salt
The isolation of C_<60> cations have been considered extremely difficult, owing to the electronegative nature of the C_<60> cage. In the present study, however, treatment of chlorides R-C_<60>-Cl with silver ion (AgSbF_6) or with a Lewis acid (SbCl_5) resulted in successful preparation of RC_<60>^+ the form of a stable solution in neutral organic solvent or in the form of a salt RC_<60>^+ SbCl_5^-. Formerly, these cations could be prepared only as solutions in strongly acidic solvents.
3.Coating of Silica Surface with Fullerene Monolayer using Alkylflullerenyl Cation
A monolayer of fullerene could be prepared on the surface of silicon wafer, by dipping the wafer in a solution of R-C_<60>-Cl. This can be interpreted as a result of the reaction of an intermediate cation RC_<60>^+ with hydroxyl groups on the surface of the oxide layer. This observation demonstrated that the high reactivity of RC_<60>^+ would be useful for the formation of a C_<60> monolayer on solid surfaces covered with hydroxyl groups.
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