Columnar liquid-crystalline compounds based on phosphine oxide: effects of structures of the flexible chains on their self-assembling behavior†

Abstract

A series of liquid-crystalline compounds based on triphenylphosphine oxide incorporating alkene-terminated side chains were designed and synthesized to examine their self-assembling behavior and responsiveness to electric fields. All compounds exhibited rectangular columnar phases, with isotropization temperatures varying based on their molecular structures. The incorporation of alkene-terminated side chains into liquid crystals in this series resulted in improved electric field responsiveness, as evidenced by the formation of fully homeotropic alignment under both direct current and alternating current electric fields. These results provide valuable insights into the structure–property relationships governing the self-assembling behavior and electric field responsiveness of the polar columnar liquid crystals, offering design principles for the development of electric field responsive materials.