Elucidation of Structure of the Second Coordination Sphere of Tris(ethylenediamine) Complex by the Isomorphous-Substitution Technique on Solution X-Ray Diffraction
Project/Area Number |
03640525
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Research Category |
Grant-in-Aid for General Scientific Research (C)
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Allocation Type | Single-year Grants |
Research Field |
無機・錯塩・放射化学
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Research Institution | Yokohama City University |
Principal Investigator |
YOKOYAMA Haruhiko Yokohama City University, Faculty of Liberal Arts and Science Associate Professor, 文理学部, 助教授 (10094319)
|
Co-Investigator(Kenkyū-buntansha) |
SHINOZAKI Kazuteru Yokohama City University, Faculty of Liberal Arts and Science Research Associate, 文理学部, 助手 (40226139)
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Project Period (FY) |
1991 – 1992
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Project Status |
Completed (Fiscal Year 1992)
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Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1992: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1991: ¥1,600,000 (Direct Cost: ¥1,600,000)
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Keywords | X-Ray Diffraction / Hydration / Solution Structure / Complex / Ethylenediamine / Second Coordination / Ion Pair / Isomorphous Substitution / X線回析 |
Research Abstract |
X-ray diffraction measurements have been carried out for aqueous solutions of chloride, bromide, iodide, perchlorate, and sulfate of tris(ethylenediamine)rhodium(III) and chromium(III) complexes. The radial distribution functions, D^<Rh>(r), around a rhodium atom were derived from the X-ray intensity data in a manner of the isomorphous substitution between Rh and Cr. The following values of metal-ligand intramolecular interactions obtained in this study were almost consistent with the crystarographic results: r_<Rh-N>=2.08A^^゚(n=6) and r_<Rh-c>=2.90-2.95A^^゚(n=6). Beyond 3A^^゚ a separated group of peaks attributable to the second coordination-sphere interactions in the vicinity of amino groups of the ligand was appeared in the region of 3.5-5.0A^^゚ of each D^<Rh>(r). The anion dependence of these peaks was found to suggest the existence of the anions in contact with the amino group. The peak area in the region of 3.5-5.0A^^゚ of D^<Rh>(r) for the perchlorate solution was smaller than th
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at for the chloride solution, while in the region of 5.0-7.5A^^゚ the situation was reverse. This means that the associated perchlorate ions exist around the methylene group and do not contribute to the distribution around 3.5-5.0A^^゚. Therefore, the peaks in D^<Rh>(r) of the perchlorate solution were attributed to the hydration water molecules and were and were analyzed by comparing theoretical curves; the water molecules were situated at 3.90A^^゚(n=2.5), 4.34A^^゚(n=4.7), and 4.85A^^゚(n=3.1). Considering this result, D^<Rh>(r) of the bromide and chloride solutions were analyzed and it was proved that the associated bromide ions existed at 4.64A^^゚(n=1) and the chloride ions at 4.50A^^゚(n=1) in both 0.3 M and 0.9 M solutions. These halide ions were considered to be in contact with the amino group by replacing one water molecule situated at 4.34A^^゚. From D^<Rh>(r) of the iodide solution meaningful results were not obtained because of its low concentration(0.06 M) due to poor solubility of the iodide. D^<Rh>(r) of the sulfate solution suggested that the associated sulfate ions were in contact with the amino group with various orientation. Less
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Report
(3 results)
Research Products
(14 results)