| Project/Area Number |
16350079
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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 | Osaka City University |
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Principal Investigator |
TEKI Yoshio Osaka City University, Material Science, Professor (00180068)
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| Project Period (FY) |
2004 – 2007
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| Project Status |
Completed (Fiscal Year 2007)
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| Budget Amount *help |
¥16,270,000 (Direct Cost: ¥15,700,000、Indirect Cost: ¥570,000)
Fiscal Year 2007: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000)
Fiscal Year 2006: ¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 2005: ¥4,100,000 (Direct Cost: ¥4,100,000)
Fiscal Year 2004: ¥7,500,000 (Direct Cost: ¥7,500,000)
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| Keywords | photo-excited high-spin state / spin alignment / one-electron oxidation / ground state triplet cation / photo-induced electron transfer / electron spin resonance / spin-nolarized electron donor / control of electronic state / π共役系 / π共役スピン系 / カチオンラジカル / 基底三重項状態 / パルスESR / 電子移動 / ドナー / アクセプター / 光励起高スピン状態 / 過渡吸収 / 電気化学的性質 / 電荷移動結晶 / 時間分解過渡吸収 |
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| Research Abstract |
Goal of this research is to control the electronic states and the physical properties of n-conjugated organic spin systems with photo-excited high-spin, states using external stimuli. The aim of this project is to find out key knowledge to the goal. The following new findings were obtained through this project.
(1)According to the proposal, the correlation between the photo-induced electron transfer and the spin alignment were investigated. New n-radicals with functionality groups were synthesized and. their photo-excited spin alignments were clarified. In particular, a unique, dynamic electron-spin polarization(DEP) was detected for the quartet photo-excited state of a novel it-radical, which consists of a bodipy acceptor (A), a anthracene donor(D), and a verdazyl radical (R). This is the first detection of a photo-excited quartet state generated via the charge-separated ion pair state of an `organic molecule. This means that "photo-synthetic DEP pattern" reported, hitherto only in the
… More
reaction center of photosystems and their model systems has been first observed in the quartet high-spin state.
(2) The cationic state of the n-radical with photo-excited quartet high-spin state was generated by an electro-chemical oxidation and the spin alignment in the electronic ground state was investigated. The triplet ground state was proven by the temperature dependence of ESR and the spin alignment was discussed by the ab-initio MO calculation. This results show that the photo-excited high-spin n-radicals play the role of the spin-polarized donors. This finding open the way for the photo-control of magnetism using the photo-excited high-spin states.
(3) A unique lowest triplet photo-excited state constructed from four unpaired electrons was investigated and the unique electronic states and the spin dynamics were clarified by time-resolved ESR and pulsed ESR.
(4) The stable π-radicals attaching dimethylamino group were synthesized. Their electronic states and physical properties of the photo-excited states as well as the ground states were clarified. The charge-transfer complexes were also synthesized and the optical and magnetic properties were investigated. Less
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