2004 Fiscal Year Final Research Report Summary
Development of molecular spectroscopy with the use of femtosecond light pulses in the near-infrared spectral region
| Project/Area Number |
15350005
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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 |
Physical chemistry
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| Research Institution | The University of Tokyo |
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Principal Investigator |
IWATA Koichi The University of Tokyo, School of Science, Associate Professor, 大学院・理学系研究, 助教授 (90232678)
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| Project Period (FY) |
2003 – 2004
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| Keywords | femtosecond / time-resolved / near-infrared spectroscopy / electron-transfer reaction / bianthryl / titanium oxide |
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| Research Abstract |
1. Formation of charge-transfer state in bianthryl
Bianthryl is formed by two anthracene rings connected by a C-C bond. When this molecule absorbs a photon, an electron is migrated from one of the anthracene rings to the other. This is one of the most basic and simplest chemical reactions. By using femtosecond time-resolved near-infrared spectroscopy, the locally excited (LE) state and the charge transfer (CT) state are clearly observed as separate transitions. It has been concluded that the LE state generated by the photoirradiation of bianthryl in acetonitrile solution is directly converted to the CT state.
2.Carrier dynamics in titanium oxide
Because the wavelength of the probe light is longer than visible or ultraviolet spectroscopies, it is possible to apply time-resolved near-infrared spectroscopy to scattering samples with the transmission method. By using this advantage, the head investigator and his collaborators have applied femtosecond time-resolved near-infrared spectroscopy t
… More
o the powder samples of titanium oxide photocatalyst (TIO4, 20 nm in diameter). They successfully observed an electron relaxation process that occurs within 1 ps, electro-hole recombination processes in several tens of picoseconds, and an electron migration process from titanium oxide to platinum co-catalyst in 2 ps. The results explain the mechanism of the increase of catalytic activities when platinum co-catalyst is loaded to titanium oxide particles.
3.Nature of charge-transfer state of symmetrically and asymmetrically substituted bianthryls
Time-resolved near-infrared spectra of symmetrically and asymmetrically substituted bianthryls have been measured. CT state absorption bands in the near-infrared region were observed only for the symmetrically substituted bianthryls ; they were not observed for the asymmetrically substituted bianthryls. It is strongly suggested that the CT absorption band observed in the near-infrared region represents the charge resonance interaction between the two anthracene rings. Less
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Research Products
(6 results)
