O-Acylcholines (OACs), which are true cationic lipids due to the quaternary ammonium functionality in the headgroup, exhibit interesting biological activities and medicinal properties. In the present study, a homologous series of OACs with even chain lengths (n= 12–20) have been synthesized, and their thermotropic and chaotropic phase transitions have been characterized. The role of various anions (Cl–, Br–, I–, NO3–, SO42–, ClO3–, ...