Syntheses and polymerizations of dialkyldiallylammonium bromides as vesicles in solution

Dialkyldiallylammonium salts 1a–c were prepared by quaternization of diallylamine with alkyl bromides and their polymerizability as oriented molecular assemblies in aqueous solution is discussed. Thin films of those ammonium salts on the glass wall were incubated by adding a phosphate buffer solution to yield giant spherical vesicles with diameters ranging from 10 to 100 μm. When large amounts of the ammonium salt were applied, it was necessary to add more than 5 mol‐% of cholesterol in order to stabilize the resulting giant vesicles. By ultrasonication of the film‐aqueous solution system, much smaller vesicles with diameters ranging from 0,03 to 0,2 μm were obtained. The stabilizing effect of cholesterol addition to the system of the small vesicles is similar to that observed for the giant vesicles. Under an inert atmosphere, the vesicles in aqueous solution were polymerized by ultraviolet irradiation. From the results of TEM and NMR spectroscopy, it was concluded that the molecules were polymerized in the vesicles without changing the profile of molecular assembly during an irradiation of 6 h. However, when the ammonium salts were dissolved homogeneously in degassed benzene, the ultraviolet irradiation polymerization did not proceed beyond a conversion of 5% under the same conditions.