1987 Fiscal Year Final Research Report Summary
Development of Highly Selective Crown Ethers through Refined Molecular Design
| Project/Area Number |
61550645
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Synthetic chemistry
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| Research Institution | Himeji Institute of Technology |
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Principal Investigator |
HAKUSHI Tadao Himeji Institute of Technology, 工学部, 教授 (70047562)
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| Co-Investigator(Kenkyū-buntansha) |
INOUE Yoshihisa Himeji Institute of Technology, 工学基礎研究所, 助教授 (30112543)
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| Project Period (FY) |
1986 – 1987
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| Keywords | crown ether / lariat ether / cation selectivity / イオン選択性 |
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| Research Abstract |
16-Crown-5, though less-symmetrical as compared with the common 3mcrown-m, has relatively high cation selectivity for Na^+ over K^+ and for Ag^+ over Tl^+. We have therefore selected this unique compound as a basis for the highly selective crown ether, and have yielded the following results.
1) In order to enhance Na^+/K^+ selectivity, we introduced sidearm(s) carrying donor atom(s) into 16-crown-5 to give single- and double-armed lariat ethers. The cation-selectivity measured by conductometric study showed Na^+/K^+ electivity of 150 for the optimized 16-crown-5 lariat with two oxygen atoms in a sidearm.
2) The effective donation by the sidearm was unequivocally improved by the characteristic bathochromic shift of the absorption maximum of the counter anion picrate extracted into organic phase. This method has also been shown to be a convenient and reliable method to evaluate the geometry of cation-ligand complexes in the solution phase, which is usually hard to hnow.
3) Efforts to enhance ag^+ selectivity by introducing a double bond as a pidonor in the sidearm is unsuccessful, which in turn indicates that the pipi interaction between a soft Ag^+ ion and a soft pi-electrons of a double bond is not so strong.
4) Since a highly Na^+ selective 16-crown-5 derivative was obtained in this study, we are now pursuing a joint project to develop highly ion-selective electrode and membrane-transport system.
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Research Products
(8 results)
