Thermal Properties of Cholesteryl and β-Sitosteryl Esters: The Effect of the Rigid Core on the Thermal Stabilities of Cholesteric and Smectic A Phases

Article abstract of DOI:10.1021/j100276a037

The effect of a central linkage X on the thermal stabilities of the cholesteric and smectic A phases of cholesteryl and β-sitosteryl esters of 4-aryl-X-benzoic and 4-aryl-X-cyclohexanecarboxylic acids (X=-COO-, -CH=N-, -N=N-, -CO-, etc.) has been examined.In both series, the cholesteric-isotropic and smectic A-cholesteric transition temperatures and the transition enthalpies are discussed in terms of the molecular structures and also the angular correlation parameter J₂₂ of the carboxy functions.The transition enthalpies for the smectic A-cholesteric transition are also discussed in terms of the McMillan theory.