Influence of rigid core structure on layer tilt and mesomorphic properties in homologous series of three ring antiferroelectric esters

Mesomorphic properties (phase transitions enthalpies and temperatures) and the dependence of smectic layer spacings upon reduced temperature for eight homologous series of three ring ester such as: (S)-(+)-4-(1-methylheptyloxycarbonyl)phenyl or (S)-(+)-4-(1-methylheptyloxycarbonyl)-3-fluorophenyl or (S)-(+)-4-(1-methyl-heptyloxycarbonyl)-2-fluorophenyl 4'-(perfluoroalkanoyloxyhexyloxy)biphenylates and 4'-(alkanoyloxyhexyloxy)-biphenylates, and (S)-(+)-4-(1-methylheptyloxycarbonyl)biphenyl-4-yl 4'-(perfluoroalkanoyloxyhexyloxy)benzoates and 4'-(alkanoyloxyhexyloxy)benzoates were described. The terminal chain fluorinated compounds have SmC*anti-SmC*-SmA-Iso phase sequence and a high tilted (orthoconic) antiferroelectric phase in broad temperature range.