Abstract

A series of cholesteryl 4’-alkyloxybiphenyl-4-carboxylates (C_nH_2n+1OC₆H₄ C₆H₄COOCh, where Ch = cholesteryl) possessing different length of alkyl chain (n = 6, 8, 10, 12, 14, 16, 18) were synthesized and their molecular structures were proposed via physical measurement and spectroscopic techniques. Phase transition temperatures and thermal parameters were obtained from differential scanning calorimetry. Observation under polarizing optical microscope revealed all the members of the series exhibiting fan-shaped texture which can be assigned to the SmA phase. Additional mesophase was observed for lower members whereby C6-14 derivatives displayed fan-shaped and oily streaks textures of cholesteric phase. The influence of structural changes (core structure and terminal chain) on the mesomorphic properties is discussed.

Key words: Cholesteryl ether, biphenyl, cholesteric, smectic A.