| Project/Area Number |
16510079
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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 |
Nanostructural science
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| Research Institution | Institute for Molecular Science |
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Principal Investigator |
TSUKUDA Tatsuya Institute for Molecular Science, Research Center for Molecular Scale Nanoscience, Associate Professor, 分子スケールナノサイエンスセンター, 助教授 (90262104)
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| Co-Investigator(Kenkyū-buntansha) |
NEGISHI Yuichi Institute for Molecular Science, Research Center for Molecular-Scale Nanoscience, Research Associate, 分子スケールナノサイエンスセンター, 助手 (20332182)
NAGATA Takashi The University of Tokyo,Graduate School of Arts and Sciences, Department of Basic Sciences, Professor, 大学院・総合文化研究科, 教授 (10164211)
NOBUSADA Katsuyuki Institute for Molecular Science, Department of Theoretical Studies, Assistant Professor, 理論分子科学研究系, 助教授 (50290896)
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| Project Period (FY) |
2004 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥2,900,000 (Direct Cost: ¥2,900,000)
Fiscal Year 2005: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2004: ¥2,200,000 (Direct Cost: ¥2,200,000)
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| Keywords | gold cluster / thiol / PAGE / mass analysis / photoluminescence / GPC / グルタチオン / エレクトロスプレーイオン化質量分析 / バンド内吸収 |
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| Research Abstract |
We have developed a synthetic method of thiolate-protected gold clusters with well-defined chemical compositions. The method is based on size separation by using polyacrylamide gel electrophoresis (PAGE) and gel permeation chromatography (GPC) and mass spectrometric characterization. Electronic and geometrical structures of the thiolated gold (Au : SR) clusters thus synthesized were studied by using various spectroscopic methods and theoretical calculations. The findings are summarized as follows.
1)The Au : SR clusters formed by reduction of the corresponding Au(I)-SR polymer correspond to trapped intermediates of the growing clusters. We observed several magic-numbered gold clusters such as Au25(SG)18 and Au55(SC18)32, where GSH and C18SH represent glutathione and octadecanethiol, respectively.
2)The small Au : SR clusters exhibit photoluminescence with quantum yield of 10^<-3>- 10^<-4>, which is significantly larger than that of bulk gold (10^<-10>). This enhancement is attributable to the quasi-molecular electronic structures. The emission wavelengths are nearly constant irrespective of the core size. This suggests that the PL originates from the Au-SR ring structures attached on the gold cluster surface. This structure model is supported by theoretical studies.
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