1992 Fiscal Year Final Research Report Summary
Synthesis of Photochromic Compounds with Excellent Thermal Stability and Fatigue Resistivity
| Project/Area Number |
03640443
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
有機化学一般
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| Research Institution | YOKOHAMA NATIONAL UNIVERSITY,FACULTY OF ENGINEERING |
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Principal Investigator |
YOKOYAMA Yasushi Yokohama National University,Faculty of Engineering,Associate Professor, 工学部, 助教授 (60134897)
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| Co-Investigator(Kenkyū-buntansha) |
YOKOYAMA Yayoi Tokyo Kasei Gakuin University,Faculty of Home Economics,Senior Lecturer, 家政学部, 専任講師 (70142263)
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| Project Period (FY) |
1991 – 1993
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| Keywords | FULGIDE / FULGENOLIDE / PHOTON MODE / OPTICAL MEMORY / FATIGUE AND THERMAL RESISTIVITY / OUANTUM YIELD / UV STABILIZER |
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| Research Abstract |
Fulgides are potential organic photochromic compounds applicable to rewritable high-density optical memory media. We have already succeeded to improve the photochromic nature of fulgides, such as to give fulgides (1) high efficiency of photoreaction and (2) responsibility to the diode laser light (780nm). The purpose of this research was to give fulgides (1) sufficient thermal stability and (2) high resistivity toward repetitive photochromic reactions.
As the acid anhydride moiety is apparently labile to alcohols, amines, and other molecules possessing active hydrogen atoms, we first substituted the acid anhydride moiety of the indolylfulgide with diesters. It indeed improved the resistivity toward hydrolysis, the quantum yields of photochromic reactions became small, as well as the absorption maximum of the colored species shortened. We then synthesized a lactone, a compound that one carbonyl group close to the aromatic ring was reduced to methylene. Although the absorption maximum of the colored from was shorter than the corresponding fulgide, the quantum yields of the photochromic reactions were far larger than those of fulgides.
As another approach to make a photochromic system stable, we also investigated the effect of addition of UV stabilizing reagents to the polymer films containing furylfulgides. Both hindered amines and hindered phenols worked quite well to protect fulgides from fatigue, and a reagent having both hindered amine and hindered phenol prohibited 85% of decomposition of the fulgides.
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