Self‐Assembly of Aminocyclopropenium Salts: En Route to Deltic Ionic Liquid Crystals

Aminocyclopropenium ions have raised much attention both as organocatalysts as well as redoxactive polymers. The self-assembly of amphiphilic aminocyclopropenium ions remains challenging however. Here the first deltic ionic liquid crystals based on aminocyclopropenium ions have been developed. Differential scanning calorimetry (DSC), polarizing optical microscopy (POM) and X-ray diffraction (WAXS, SAXS) provided insight into the unique self-assembly and nanosegregation of these liquid crystals. While the combination of small headgroups with linear p -alkoxyphenyl units led to bilayer-type smectic mesophases, wedge-shaped units resulted in columnar mesophases. Upon increasing the size and polyphilicity of the aminocyclopropenium headgroup again a lamellar phase was formed.