SYNTHESES WITH NITRILES .98. SYNTHESIS AND CHARACTERIZATION OF (AMINOCYANOMETHYLENE)INDANDIONE AND (AMINOCYANOMETHYLENE)PYRAZOLONE CHROMOIONOPHORES AS EXTRACTANTS FOR ALKALI-METAL IONS

A new approach to dissociable chromoionophores 5, 6a-e, 7 and 8 by rea ction of (dicyanomethylene)indandione 1 and (dicyanomethylene)pyrazolo nes 2a-e, respectively, with aminophenyl crowns 3 and 4 is described. The complexation constants were determined by H-1-NMR spectroscopy. Fo r 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 th e nature of the crown (aza-crown or benzo-crown with the same ring siz e) are discussed by comparison with a series of known crowns and also on the basis of molecular modelling techniques. The ability of the chr omophore 6a as extractant for sodium and potassium ions in its ionic f orm is shown.