2006 Fiscal Year Final Research Report Summary
Control of Photoluminescence properties of semiconductor nanoparticles through the design of surface pi-functionalities
| Project/Area Number |
17350062
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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 |
Functional materials chemistry
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| Research Institution | Hokkaido University |
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Principal Investigator |
KONISHI Katsuaki Hokkaido Univ. Fac. of Env. Earth Sci., Asso. Prof., 大学院地球環境科学研究院, 助教授 (80234798)
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| Project Period (FY) |
2005 – 2006
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| Keywords | Enivoronmental materials / Molecular recognition / supramolecular chemistry / semiconductor nanoparticles |
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| Research Abstract |
Semiconductor nanoclusters of cadmium chalcogenides have been of great interest due to their characteristic photoluminescence (PL) properties. These clusters usually bear multiple surface capping modules that potentially server as guest binding sites. Recently we have reported that Cd_10S_4(SPh)_12 (1) with twelve surface phenyl groups the easily form ionic complexes with quaternary ammonium bromide by coordination of bromide anions to the apex cadmium atoms. We have also shown that small cations such as cetyltrimethylammonium ion (CTA^+) are intercalated among the surface phenyl groups of 1 through cation-pi interaction and such intercalative binding causes notable positive response of the cluster PL. In this project we investigated the effects of electron withdrawing and donating substituents attached to the surface phenyl groups of 1 on the cluster optical properties. When electron-withdrawing substituents, such as ester and chloro, were introduced, the cluster PL band was shifted to a higher energy (blue shift) and the quantum yield was increased. In contrast, when electron-donating substituents, such as methoxy and methyl, the PL band was reduced and red-shifted. We also investigated the PL response of an analogous cluster with hydrophilic substituents towards metal ions in aqueous solutions.
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