Self-assembly of chiral mesoionic heterocycles into smectic phases: a new class of polar liquid crystal

The molecular design, synthesis and characterization of the first examples of both classical and non-conventional chiral mesoionic (mesomeric + ionic) liquid crystals derived from sydnones are described. The occurrence of chiral smectic phases in these novel compounds was evidenced by optical microscopy, calorimetry and X-ray studies.