| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2003: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 2002: ¥2,400,000 (Direct Cost: ¥2,400,000)
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| Research Abstract |
Two main objectives of the project are : (1) study on the strategies for constructing supracomplexes, and (2) developments of supramolecules with new functions. For (1), following two strategies have been explored ; (1)how to control the aurophilicity which is one of the new self-assembly techniques and how to create new molecular Au dusters and (2)how to control the dimensionality of the coordination polymers. For the synthesis of new functional supramolecules (2), following three categories of supramolecules have been targeted ; (3)single molecular magnets, (4) micro-reactor, and (5)tuminescent molecular wires.
[Results](1) Control of the aurophilicity and the creation of new molecular Au clusters : 1. As one of the best results, synthesis and molecular structure analysis of Au_<11>(SR)_3(PR_3)_7 should be mentioned ; the significance of the result is clear because of the recent avalanche of studies on SR-modified gold particles. The next significant result is the first synthesis and
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x-ray molecular structure analysis of Au_<19> cluster. 2. The successful synthesis of the first generation dendrimers of the (R'_3PAuS)_3R by introducing the AuPR'_3 moiety into the S_3R scafollding (R=benzene and/or triazine). It has been also clarified that the advent of aurophilicity and the structure of the resulting Au supramolecules have been controlled by modifying the R' group. 3. It has been also clarified that the advent of aurophilicity and the structure of the resulting Au supramolecules have been controlled by changing R and R' for (RS-Au)_2(P-R'-P) and that the compactness around Au is the most important factor for aurophilicity.. 4. The synthesis and x-ray molecular structure analysis have been successfully made for hetero-mtal supramolecules by coordinating the Au(4-S-py)PR_3 as a "complex as a ligand" to other transition metal complexes such as Cr-acac and Cu-hfac. (2)How to control the dimensionality of the coordination polymers : in order to create new supramolecules with nano-channel structures, Zn(II) ion was employed as a grid metal ion and pyrazine carboxylate and 4,4'-bipyridine derivatives were employed as a linker ligand. Four types of new grid frameworks have been synthesized and their nano-structures have been clarified by x-ray structure analysis. Among them, the cage structures of two complexes have been survived after the removal of the solvent molecules. This behavior indicates that the resulting cage structure should be used as a "micro-reactor".
(2) Developments of supramolecules with new functions : (3) synthesis of single molecular magnet :: synthesis, x-ray structure analysis, and magnetic data measuranents have been made for Mn_4(pyMOH)_6(H_2O)_5](ClO_4)_4. AC magnetization measurements down to 1.7K have shown that the duster is one of the single molecular magnets. (5) Heteronudear Ru_mAu_n(bpy)_x(o-phen)_y-type complexes have been synthesized by combining Ru-(bpy) and o-phen-Au-L up to Au_4Ru_3. As both metals are known to be fluorescent, new optical behavior has been expected. Indeed, excitation on Au site results fluorescence from the Ru site (6)Other results : 1. Creation of huge single crystals of Mn_3(C_6F_5CO_2)_6(py)_3. This success has made it possible to obtain rotational angle dependent ESR signals by use of single crystal and the measurements about two main crystal axes and analysis have been successfully made for the first time. 2. The versatility of pyridine-alcohol derivatives as a ligand toward manganese ion has been clarified by the synthesis of a series of coordination complexes. Less
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