Aqueous suspensions of N,N-Dihexadecyl-l,2-ethanediarnine-N:N'-diacetic acid (1 d) give stable vesicles on sonication at pH = 3.5 and 9.0. The outer vesicle surface chelates copper(I1) and iron(lI1) ions without vesicle precipitation. Chelating micelles'.*) and vesicles are of interest because they allow the attachment of redox-active metal ions. If the aggregate also contains a photochemically active dye, e.g. a porphyrin, such systems may be used for light-induced charge separation3'. We report here on the synthesis and chelating properties of a vesicle with ethylenediaminediacetic acid head groups.The title compound Id was prepared from N-(2-aminoethyl)acetamide (1 a) by dialkylation with hexadecyl bromide in ethanol to give l b , removal of the acetyl protecting group in ethanolic sodium hydroxide and treatment of l c with chloroacetic acid in dirnethylformamide. The overall yield was 28 070.Ultrasonication of aqueous suspensions of 1 d gave stable, slightly opaque solutions at pH = 2 and 9. At pH = 6 the clear solution became turbid within a few hours.Electron micrographs of the evaporated solutions indicated the presence of vesicles with diameters ranging from 500-2000 A (Fig. 1). Water insoluble magnesium octaethylporphyrin could be dissolved t o a concentration of about molar in the vesicular solutions.
Aus Ethylendiamin (Ia) wird die im Titel genannte Diessigsäure (le) hergestellt, die bei der Behandlung mit Ultraschall in wäßriger Suspension Vesikel ergibt, die bei pHi = 3.5 und 9.0 stabil sind und an der äußeren Oberfläche Kupfer(ll)‐ und Eisen(III)‐Ionen chelatisieren, ohne daß die Vesikel ausfallen (Abb.
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