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Syntheses with Nitriles, XCVIII Synthesis and Characterization of (Aminocyanomethylene)indandione and -pyrazolone Chromoionophores as Extractants for Alkali Metal Ions

✍ Scribed by Boila-Göckel, Andrei ;Fabian, Walter M. F. ;Junek, Hans


Publisher
John Wiley and Sons
Year
2006
Tongue
English
Weight
568 KB
Volume
1996
Category
Article
ISSN
0947-3440

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✦ Synopsis


Abstract

A new approach to dissociable chromoionophores 5, 6a–e, 7 and 8 by reaction of (dicyanomethylene)indandione 1 and (dicyanomethylene)pyrazolones 2a–e, respectively, with aminophenyl crowns 3 and 4 is described. The complexation constants were determined by ^1^H‐NMR spectroscopy. For the chromoionophores 5 and 6a–e bearing a benzo[15]crown‐5 moiety, K~c~ values between 1100 and 1900 were found, while the chromoionophores 7 and 8 bearing the N‐phenylaza[15]crown‐5 provided binding constants which are about twenty times lower. These differences depending on the nature of the crown (aza‐crown or benzo‐crown with the same ring size) are discussed by comparison with a series of known crowns and also on the basis of molecular modelling techniques. The ability of the chromophore 6a as extractant for sodium and potassium ions in its ionic form is shown.