Synthesis of liquid crystalline rod-coil dimers based on poly(propylene oxide) coil

Abstract

The synthesis and characterization of 4-[poly(propyleneoxy)propyloxy]-4'-bis[4-decyloxycarbonylbiphenyl-4'-biphenylcarboxylate] with poly(propylene oxide) coil of seven (dimer-7), twelve (dimer-12), seventeen (dimer-17), twenty one (dimer-21) are described. Dimer-7 with short length of poly(propylene oxide) coil exhibits successively smectic C, smectic A and nematic mesophases, while dimer-12 and dimer-17 with longer lengths of coils exhibit a bicontinuous cubic mesophase with Ia3d symmetry. Further increasing the length of coil, as in the case of dimer-21, suppresses liquid crystallinity.