Twist grain boundary smectic A phase in compounds derived from cholesterol

Abstract

The synthesis and characterization of four compounds of a homologous series of cholesteryl-2-fluoro-4-n-alkoxybenzoates is reported. The twist grain bound-ary smectic A phase was observed in three compounds which contain only one phenyl ring. All the com-pounds exhibiting this phase, also show blue phase, cholesteric, smectic A and smectic C* phases. The mesophases were identified using polarizing optical microscopy, differential scanning calorimetry and heli-cal pitch measurements.