| A1552 | 1-Aza-12-crown 4-Ether (1) |
250mg |
| A1323 | 1-Aza-15-crown 5-Ether (2) |
1g |
| A1324 | 1-Aza-18-crown 6-Ether (3) |
5g 1g |
| D2743 | 4,10-Diaza-12-crown 4-Ether (4) |
1g 100mg |
| D2744 | 4,10-Diaza-15-crown 5-Ether (5) |
1g |
| D2323 | 4,13-Diaza-18-crown 6-Ether (6) |
1g |
It is well known that crown ethers have good coordinating ability to metal ions. Armed crown ethers intoduce guest-ligating sidearms to the crown rings to form dynamic and three dimentional complexes which are attracting increased interest as intelligent molecules.1)
These compounds, 1-6, have nitrogen atoms at their crown rings, and via the introduction of sidearms by reaction with electrophiles, can be transformed in to armed crown ethers exhibiting new functionality. For example, 7 having an amine-functionalized sidearm shows high lithium ion selectivity,2) while it is formally size-fitted to the 12-crown 4-ether cavity which exhibits sodium ion selectivity.
Furthermore, armed crown ether 8, a metal-ligating sidearm which contains a chromophore, is used for the liquid-liquid extraction of alkali metal ions, and can monitor these ions by colorimetry.3)
References
H. Tsukube, Yuki Gosei Kagaku Kyokaishi (J. Synth. Org. Chem. Japan) 51, 851 (1993); H. Tsukube, Nippon Ion Kokan Gakkaishi (J. Ion Exchange) 4,
23 (1993).
2) Ion-selective binding and transport properties of amine-armed
azacrown ethers
H. Tsukube, K. Hori, T. Inoue, Tetrahedron Lett., 34, 6749 (1993); H. Tsukube, T. Inoue, K. Hori, J. Org. Chem., 59, 8047 (1994).
3) Synthesis of chromogenic crown ethers and liquid-liquid
extraction of alkali metal ions
Y. Katayama, K. Nita, M. Ueda, H. Nakamura, M. Takagi, Anal. Chim. Acta,
173, 193 (1985).
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