Refractive Indices, Densities, Polarizabilities and Molecular Order in Nematic p-Ethoxy Benzylidene-p-n- Butylaniline

Abstract

Refractive index measurements of EBBA (p-Ethoxy-Benzylidine, p-n-Butylaniline) have been made in the crystalline, liquid crystalline and liquid phases using prism technique. The principal refractive indices of the crystalline phase have been obtained by making measurements on two different specimens of crystals grown in the prisms with small angles, with molecular axis parallel and perpendicular to the prism axis respectively. Orientational order parameters have been evaluated making use of the density data of liquid crystalline phase extrapolated from the density value at one temperature in the liquid crystalline phase and the thermal expansion coefficient and the densities of the crystal and liquid measured by floatation and specific gravity bottle techniques respectively. The estimated values of the S-factors are in very good agreement with those obtained by wide line NMR studies on deuterated EBBA molecule.