| Project/Area Number |
14204067
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Inorganic chemistry
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| Research Institution | Tokyo Institute of Technology |
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Principal Investigator |
YAMASE Toshihiro Tokyo Institute of Technology, Chemical Resources Laboratory, Professor, 資源化学研究所, 教授 (80016576)
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| Co-Investigator(Kenkyū-buntansha) |
OZEKI Tomoji Tokyo Institute of Technology, Department of Chemistry and Materials Science, Associate Professor, 大学院・理工学研究科, 助教授 (60214136)
NARUKE Haruo Tokyo Institute of Technology, Chemical Resources Laboratory, Professor, 資源化学研究所, 助教授 (40237623)
ISHIKAWA Eri Tokyo Institute of Technology, Chemical Resources Laboratory, Research Associate, 資源化学研究所, 助手 (90323831)
SAWADA Keiju Tokyo Institute of Technology, Chemical Resources Laboratory, Research Associate, 資源化学研究所, 助手 (10316490)
ITO Takeru Tokyo Institute of Technology, Chemical Resources Laboratory, Research Associate, 資源化学研究所, 助手 (50376935)
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| Project Period (FY) |
2002 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥55,770,000 (Direct Cost: ¥42,900,000、Indirect Cost: ¥12,870,000)
Fiscal Year 2004: ¥7,150,000 (Direct Cost: ¥5,500,000、Indirect Cost: ¥1,650,000)
Fiscal Year 2003: ¥7,150,000 (Direct Cost: ¥5,500,000、Indirect Cost: ¥1,650,000)
Fiscal Year 2002: ¥41,470,000 (Direct Cost: ¥31,900,000、Indirect Cost: ¥9,570,000)
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| Keywords | Nanotube / Lanthanide cluster / Self-assembly / Polyoxometalates / Supercluster / Nano ring / CIDEP / Mo-blues / モリブデンブルー / スピン分極 / 時間分解ESR / ナノリングポリ酸 / 楕円リングポリ酸 / 希土類ポリ酸 / ポリ酸 / ナノサイズリング状ポリ酸 / 希土類金属 / 光誘起自己集合化反応 / X線構造解析 / 還元種 / 光化学的還元反応 / クラウン型 / アルカリ金属イオン / ビルディングブロック / 水車構造 / 風車構造 |
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| Research Abstract |
Photochemically controlled self-assembly to giant-ring structural polyoxometalate superclusters is promising for the molecular design of nano-rings in the nanostructure landscape, and has opened up a basis of nanotechnology via a bottom-up approach, starting from polyoxometalate subunits which incorporate functionalities that are appropriate for electronic/magnetic devices. A variety of novel structures and fundamentally significant properties for the polyoxometalate nano-rings have been established: (i)A combination of [AsW_9O_<33>]^<9-> (as building block) and lanthanide (Ln^<3+> as linker) led to the formation of crown-shaped polyoxotungstolanthanoate rings such as [Cs⊂Ln_4(H_2O)_8(AsW_9O_<33>)_4]^<23-> (with windmill structure) and [K⊂Ln_6(H_2O)_<12> (AsW_9O_<33>)_6]^<35-> (with watermill-propeller structure) in the presence of Cs^+ and K^+ in solutions, respectively. Interestingly, the presence of Mg^<2+> induced the formation of [{Eu(H_2O)_2}_2(AsW_9O_<33>)}_4(H_2O)_4(EuW_5O_<18>
… More
)_2]^<30-> with 3.4-nm length, (ii)Subsequent to our finding of the photoinduced formation of car-tire-shaped Mo-blue nano-rings of {Mo_<142>} and {Mo_<145>} with 3.5 nm diameter, a manipulation of pH level, concentration of Ln^<3+>, and electron donor compounds showed a wide variety of nano-ring clusters such as {Mo_<154>}∞(nano-tube), {Mo_<146>}∞(nano-chain), {Mo_<150>La_2}, {Mo_<120>Ln_6}, {Mo_<130>Ln_<10>}, and {Mo_<150>Ln(MeC_6H_4SO_2)_4} which could be photochemically controlled. The time-resolved ESR spectroscopy was employed for the clarification of initial steps of the reaction, and a pioneering mechanism for the self-assembly to nano-sized Mo-blues has been offered, (iii)It is found that three typed polyoxotungstates sandwiching spin moieties of triangle, trigonal prism, and hexagon are novel single-molecule magnets at low temperatures : for example, K_<11>H[(VO)_3(SbW_9O_<33>)_2]・29H_2O which is a spin-frustrated compound with D_<3h> anion incorporating (VO)_3^<6+>-triangle with V^<IV>…V^<IV> separation of 5.4 Å, is a good model of the magnetization between pure quantum states S=1/2 and 3/2 and provides a new class of single-molecular magnets. "International Symposium on Nano-structures and Physicochemical Properties of Polyoxometalate Superclusters and Related Colloid Particles" was organized by T.Yamase, M.T.Pope, and A.Muller with the support of the present project of JSPS at Shonan village, Kanagawa on Nov.21-25 2004,and a great success of this meeting is reported on Angew.Chem.Int.Ed., 2005, 44, 844-846. Less
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