ISSN:
1573-1111
Keywords:
Ion cleft
;
three-bridged cyclophane
;
crownophane
;
extraction
;
metal cation
;
ester
;
pyridyl group
;
aminimide
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract A variety of new three-bridged cyclophanes, clefts4–14, have been conveniently prepared, and their cation-binding properties have been examined. Compounds4–6 have a special affinity for alkali metal cations. Ethyl ester5 and methyl ester4 selectively formed 2:1 complexes with K+ and Na+ ions, respectively. Clefts11–13, which possess pyridyl groups, bind Ag+ cation exclusively.1H NMR titration studies confirmed that11 or12, having 2- or 3-pyridyl groups, form a 1:1 complex with Ag+ cation, while13, with 4-pyridyl ligating groups, forms a 2:1 complex. Cleft10, with aminimide groups, also shows an affinity for Ag+ cation in a 2:1 ratio in a polar solvent, while it forms a 1:1 complex in a nonpolar solvent. The same solvent effect was observed for clefts13 and15c, which is discussed qualitatively.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00707936
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