| Project/Area Number |
11228206
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| Research Category |
Grant-in-Aid for Scientific Research on Priority Areas
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| Allocation Type | Single-year Grants |
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| Review Section |
Science and Engineering
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| Research Institution | Osaka City University |
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Principal Investigator |
ITOH Shinobu Osaka City University, Department of Chemistry, Professor, 大学院・理学研究科, 教授 (30184659)
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| Co-Investigator(Kenkyū-buntansha) |
TACHI Yoshimitsu Osaka City University, Department of Chemistry, Assistant Prof., 大学院・理学研究科, 助手 (50336757)
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| Project Period (FY) |
1999 – 2002
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥60,700,000 (Direct Cost: ¥60,700,000)
Fiscal Year 2002: ¥7,600,000 (Direct Cost: ¥7,600,000)
Fiscal Year 2001: ¥8,000,000 (Direct Cost: ¥8,000,000)
Fiscal Year 2000: ¥14,500,000 (Direct Cost: ¥14,500,000)
Fiscal Year 1999: ¥30,600,000 (Direct Cost: ¥30,600,000)
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| Keywords | Dioxygen Activation / Dicopper-Dioxygen Comples / Peroxo Complex / Oxo Complex / Aromatic Hydroxylation / Aliphatic Hydroxylation / Oxygen Transfer Reaction / Reaction Mechanism / 活性酸素 / 反応制御 / 二核金属酸素錯体 / C-H結合活性化 / 金属酵素活性中心モデル / 酸素添加酵 / 非対称型二核遷移金属錯体 / 二核銅酸素錯 / 配位子合成 / 三核銅酸素錯体 |
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| Research Abstract |
Reaction of copper(I) complexes with molecular oxygen have been examined using a series of N-alkyl-bis[2-(2-pyridyl)ethyl]amine tridentate ligands and N, N-dialkyl-2-(2-pyridyl)ethylamine didentate ligands at low temperature. The tridentate ligands predominantly provide (μ-η^2 : η^2-peroxo)dicopper(II) complexes (side-on type peroxo complex), while the didentate ligands enhance O-O bond homolysis of the peroxo species to produce bis(μ-oxo)dicopper(III) complexes. With the (μ-η^2 : η^2-peroxo)dicopper(II) complexes supported by the tridentate ligand, efficient oxygenation of phenolates to the corresponding catechols has been accomplished to provide a good model reaction of tyrosinase. The bis(μ-oxo)dicopper(III) complexes, on the other hand, undergo aliphatic ligand hydroxylation as well as oxygen atom transfer to sulfides to give the corresponding sulfoxides. In the reaction of bis(μ-oxo)dicopper(III) complex with 10-methyl-9, 10-dihydroacridine (AcrH_2) and 1, 4-cyclohexadiene (CHD), a new active oxygen intermediate such as a (μ-oxo)(μ-oxyl radical)dicopper(III) or a tetranuclear copper-oxygen complex has been suggested to be involved as the real active oxygen species for the C-H bond activation of the external substrates. A mixed valence bis(μ_3-oxo) trinuclear copper(II, II, III) complex has also been assessed using the didentate ligand with the smallest N-alkyl substituent (methyl). Mechanistic details of the above reactions as well as ligand effects on the copper(I)-dioxygen reactivity are discussed systematically. In addition to the copper-dioxygen complexes, a similar type of nickel-dioxygen complexes as well as copper-disulfide complexes have been developed in order to provide further insights into the redox functions of metalloproteins
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