Hierarchically Mesostructured Polyisobutylene-Based Ionic Liquids.

The formation and design of a hierarchically nanostructured poly(isobutylene)-based ionic liquid (PIB-ILs) is reported, displaying assembly into classical multiplets and an additional ordering of the aromatic counteranions. Three PIB-ILs (Mn = 3600 and 8600 g mol(-1) ), bearing imidazolium (1a), N-methylpyrrolidinium (1b), and triethylammonium cations (1c) together with the aromatic 2-(methylthio)benzoate anion are prepared via a combination of living carbocationic polymerization, "click" reactions and subsequent anion metathesis. The morphology of the novel PIB-ILs as well as its temperature-dependent behavior has been studied via small angle X-ray scattering, displaying two different transition temperatures: one originating from ordering of micelles within a cylinder, and the second from cylinder-cylinder arrangement.