HETEROCYCLIC ESTERS EXHIBITING FRUSTRATED LIQUID-CRYSTAL PHASES

A series of novel heterocyclic esters has been prepared based on selen ophene, thiophene and furan units; for comparison the parent, phenyl a nalogue was also prepared. All the materials except the least linear f uran analogue are mesogenic and exhibit the S-A, S-C, S-C*ferri and S -Canti liquid crystalline phases. In addition, the selenophene materi al exhibits a higher ordered antiferroelectric phase which has been de signated the antiferroelectric smectic I (S-Ianti) phase and below th is the S-I phase was generated. The synthesis, mesomorphic behaviour and physical properties of the materials are reported.