FUKAMINATO Tsuyosi Kyushu University, Graduate School of Engineering, Research Associate (80380583)
松田 建児 九州大学, 大学院工学研究院, 助教授 (80262145)
山口 忠承 九州大学, 大学院工学研究院, 特任助手 (60295722)
小畠 誠也 九州大学, 大学院・工学研究院, 助手 (00325507)
河合 壮 九州大学, 大学院・工学研究院, 助教授 (40221197)
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¥94,510,000 (Direct Cost : ¥72,700,000、Indirect Cost : ¥21,810,000)
Fiscal Year 2007 : ¥14,430,000 (Direct Cost : ¥11,100,000、Indirect Cost : ¥3,330,000)
Fiscal Year 2006 : ¥15,340,000 (Direct Cost : ¥11,800,000、Indirect Cost : ¥3,540,000)
Fiscal Year 2005 : ¥19,760,000 (Direct Cost : ¥15,200,000、Indirect Cost : ¥4,560,000)
Fiscal Year 2004 : ¥23,790,000 (Direct Cost : ¥18,300,000、Indirect Cost : ¥5,490,000)
Fiscal Year 2003 : ¥21,190,000 (Direct Cost : ¥16,300,000、Indirect Cost : ¥4,890,000)
The ultimate goal of optical memory is to store optical information in each molecule. As the first step to the single-molecule optical memory, we carried out the synthesis of fluorescent photochromic molecules suitable for the optical memory and measured the photo-switching of fluorescence from the single molecules. The photochromic molecule should exhibit the following performance ; high photo-switching efficiency, a fatigue resistant property and a high fluorescent quantum yield. It is also required to reveal the detailed mechanism of single-molecule photochemistry. The results are as follows.
(1) Fluorescent photochromic molecules having a fluorescent anthracene or perylene unit and a photochromic diarylethene unit were synthesized. When the two units are connected by an adamantyl group, the molecules exhibit efficient photo-switching performance and high fluorescent quantum yields. Molecules which show electron-transfer fluorescent quenching were also prepared.
(2) The above newly synthesized molecules were dispersed in various polymer matrices and the photo-switching of fluorescence from the single molecules was measured. The fluorescence showed a digital photo-switching in two states and the response times(on and off times) were found to show a broad distribution. The distribution of the response times was studied theoretically in detail and attributed to local minima in both ground and excited energy diagrams. This finding surely provides a new insight into the photochemistry in polymer matrices.