| Project/Area Number |
11640603
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
分離・精製・検出法
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| Research Institution | IBARAKI UNIVERSITY |
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Principal Investigator |
IMURA Hisanore IBARAKI Univ., Faculty of Sci., Prof., 理学部, 教授 (60142923)
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| Co-Investigator(Kenkyū-buntansha) |
OHASHI Kousaburo IBARAKI Univ., Faculty of Sci., Prof., 理学部, 教授 (60007763)
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| Project Period (FY) |
1999 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2000: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 1999: ¥2,500,000 (Direct Cost: ¥2,500,000)
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| Keywords | rare earth / solvent extraction / synergistic effect / complex ligand / hydrogen bonding / 水素結合 |
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| Research Abstract |
Effect of cobalt (III) chelates such as tris (4-isopropyltropolonato)cobalt (III)(Co (ipt)_3) and tris (acetylacetonato) cobalt (III)(Co (acac)_3) for comparison on the extraction of rare earth ions (RE) with β-diketones (HA) has been studied. The extraction of RE with thenoyltrifluoroacetone (Htta) or hexafluoroacetylacetone (Hhfa) in benzene or toluene was remarkably enhanced by the addition of those cobalt (III) chelates, especially Co (ipt)_3 in the Hhfa-toluene system. This is the synergistic effect caused by the cobalt (III) chelates. From the equilibrium analysis, the synergism was ascribed to the formation of a 1 : 1 adduct of RE (A)_3 with the cobalt (III) chelate in the organic phase and the adduct formation constant (β_*) was determined. The β_* values decreased with decrease in the ionic radius of RE and gave the large differentce between light and heavy RE.Some spectroscopic studies such as electronic absorption and infrared absorption were performed to explain such difference in β_* From the IR spectra, the displacement of the coordinated water molecules of the light RE chelates such as Nd (Eta)_3 with Co (ipt)_3 was observed ; therefore, the direct coordination of Co (ipt)_3, toward the central metal of the RE chelate. On the other hand, the adduct formation of heavy RE was ascribed to the hydrogen bonding between Co (ipt)_3 and the coordinated water molecules of the RE chelates. It was proved that the coordinately saturated cobalt (III)-ipt chelate acts as a complex ligands and causes the synergistic enhancement of the extraction of RE.
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