| Project/Area Number |
02453080
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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 |
工業物理化学・複合材料
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| Research Institution | Kyushu University |
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Principal Investigator |
MATSUO Taku Kyushu University Department of Chemical Science and Technology Professor, 工学部, 教授 (30037725)
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| Co-Investigator(Kenkyū-buntansha) |
YONEMURA Hiroaki Kyushu University Department of Chemical Science and Technology Assistant, 工学部, 助手 (40220769)
NAKAMURA Hiroshi Hokkaido University Department of Chemistry Professor, 理学部, 教授 (00117194)
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| Project Period (FY) |
1990 – 1991
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| Project Status |
Completed (Fiscal Year 1991)
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| Budget Amount *help |
¥5,900,000 (Direct Cost: ¥5,900,000)
Fiscal Year 1991: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 1990: ¥4,500,000 (Direct Cost: ¥4,500,000)
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| Keywords | Donor-Acceptor Linked System / Ruthenium Polypyridine Complex / Optical Second Harmonic Generation (SHG) / Electron-Transfer / Langmuir-Blodgett Film / Magnetic Field Effects / 表面吸着 / 光誘起電子移動 / DonorーAcceptor結合系 |
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| Research Abstract |
Passive optical switching will be achieved, if photoinduced electron-transfer is associated with a new absorption band of a radical pair to cut off a light beam. Active switching should be observed, when the electrontransfer process is accompanied by light emission.
(1) Transient absorption due to photogenerated radical pairs was investigated by the use of viologen as the electron acceptor (A). Either porphyrin or phenothiazine unit was the electron donor (D). The radical pair was easily generated, when the D and A were held each other within 1.5 nm. The lifetime of the radical pair was a few microseconds, but it could be easily extended up to 10 microseconds in the presence of external magnetic fields above 0.3 T. Photogeneration of the radical pairs was facilitated by molecular complexation. Transient absorption due to the radical pair could be used to construct passive switching elements.
(2) Optical Second-Harmonic Generation (SHG) was observed by the use of amphiphloic ruthenium complexes incorporated into LB films. Metal to ligand charge-transferred state (MLCT) was responsible to the SHG. The intensity of the SHG at 532 nm could be remarkably reduced on laser excitation of the ML CT transition. This is the first observation of optical modulation of SHG intensity. Active switching should be achieved by virtue of this phenomenon.
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