2004 Fiscal Year Final Research Report Summary
Construction of Metallo-nano Architecture Possessing Cooperative Functions
| Project/Area Number |
15350076
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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 | University of Tsukuba |
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Principal Investigator |
NABESHIMA Tatsuya University of Tsukuba, Graduate School of Pure and Applied Sciences, Professor, 大学院・数理物質科学研究科, 教授 (80198374)
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| Co-Investigator(Kenkyū-buntansha) |
AKINE Shigehisa University of Tsukuba, Graduate School of Pure and Applied Sciences, Assistant Professor, 大学院・数理物質科学研究科, 講師 (30323265)
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| Project Period (FY) |
2003 – 2004
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| Keywords | Helical Structure / Bipyridine / Macrocyclic Compound / Host-guest / Supramolecule / Oxime / Mutinuclear Commplex / Allosteric Effect |
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| Research Abstract |
We have designed and synthesized various metallo-nano molecular systems possessing cooperative functions, which respond to external stimuli. The basic structures are pseudomacrocyclic, pseudomacrobicyclic and C-shaped metallo frameworks. For example, a pseudocryptand obtained from reaction of a tripodand bearing bipyridines with Fe(II) exhibited both positive and negative allosteric effects on recognition of alkali metal ions. This new type of regulation is achieved by control of induced-fit recognition. In addition, upon the complexation of the helical pseudocryptand with cesium ion the metallohost is elongated and twisted in a spring like fashion. The responding structural change may be applied to nano-molecular machines. We have also prepared a novel linear oligooxime ligand, which is quantitatively and cooperatively converted to a C-shaped trizinc complex. During the complexation formation of the mono-and dizinc complexes was not observed. Interestingly, only one zinc atom captured in the center of the C-shaped binding site was replaced quantitatively by lanthanide and calcium. The selectivity of calcium among alkaline earth metals is extremely high and comparable to those of famous calcium binders. A new Cu,Gd heterotririuclear complex, which exhibits ferromagetic interaction, was also prepared according to this effective transmetalation method. A multi-responding anion receptor was synthesized by using a calix[4]arene framework. The anion recognition was controlled stepwise and dramatically by cations as an effector.
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