Induced smectic mesomorphism in binary mixtures of cholesteryl chloride and 4,4'-diheptyloxyazoxybenzene

Abstract

We report here the occurrence of an 'Induced Smectic A' phase in binary mixtures of cholesteryl chloride (ChCl) and 4,4'-diheptyloxyazoxybenzene (HOAB). It is interesting to find that cholesteryl chloride, which is not as strongly polar as cyano- or nitro group containing aromatic nematogens, gives rise to the induced smectic phase.

X-ray studies on ChCl, HOAB and their mixtures show that neither the pure compounds nor the mixtures have a bilayer arrangement of molecules. The interesting result is obtained that in a 12 mole pet ChCl in HOAB mixture, which exhibits a twisted smectic C phase and a skew-cybotactic cholesteric phase, the tilt angle varies with temperature, although in the corresponding smectic C and skew-cybotactic nematic phases of pure HOAB, the tilt angle is independent of temperature.