Lateral fluoro-substitution driven molecular packing difference in a series of pyridinium-based chiral ionic liquid crystals

Abstract

ABSTRACT A series of pyridinium-based chiral ionic liquid crystals (ILCs) and the intermediated, non-ionic ones (NILCs), were designed and synthesised. All ILCs exhibit enantiotropic SmA phases, while all NILCs exhibit enantiotropic cholesteric and SmA phases. In addition, few of NILCs and ILCs exhibit enantiotropic SmC* phases. Due to the Coulombic force, the clearing points of the ILCs are higher than those of the corresponding NILCs. For ILCs, the lateral fluoro-substitution not only decreases the clearing points, but also drives the formation of bilayer molecular packing structures at the smectic phases.