Monolayer and Bilayer Vesicle Membranes from p ‐Phenylenediamine Derivatives

Several water‐insoluble (pH 4 or 2) N,N ‐dialkylated p ‐phenylenediamine derivatives form bilayer membrane vesicles on sonication under nitrogen. Corresponding α,ω‐betaines give vesicles with monolayer membranes on sonication. In electron micrographs chain‐like aggregates are observed. – The free amino group on the outer surface of the phenylenediamine vesicles reacts selectively in an oxidative coupling reaction with phenol and acetanilide and pyrazolone derivatives as well as with nitrite ions. Vesicles with coloured outer surfaces (blue, red, and yellow) are obtained. The inner surface does not react. Small coupling reagent molecules react much faster with the vesicles than large ones. In ethanolic solution such differences are not observed.