Density, Refractive Index and Ultrasonic Velocity Studies Involving N(p-n-Hexyloxy Benzylidene) p-n-Octyl Aniline

Abstract

The density, refractive index and ultrasonic velocity dependence on temperature for N(p-n-hexyloxy benzylidene) p-n-octyl aniline, 60.8, is presented. The compound exhibits smectic B, smectic A, nematic and monotropic smectic G phases between the solid and isotropic liquid phases. The nematic—isotropic and smectic A—smectic B phase transitions are found to be first order. The interesting nematic—smectic A transformation is confirmed to be a first order from the observed results. An estimate of the pressure dependence of the phase transition temperatures using the volume and enthalpy data are presented. A comparison of these results with other reported results in the homologous series of n0.m compounds are also discussed.