Structure of the Smectic-BPhase and the Nature of the Smectic-Bto -HTransition in the N-(4-n-Alkoxybenzylidene)-4′-Alkylanilines

Abstract

The phase behavior and structures of several liquid crystals of the $n\mathrm{O}.\mathrm{}m$ (${\mathrm{C}}_n{\mathrm{H}}_{2n+1}-\mathrm{OPhCHNPh}{\mathrm{C}}_m{\mathrm{H}}_{2m+1\mathrm{}}$) series of compounds have been established by a variety of experiments. The hexagonal close-packed layers of the $S_B$ phases have a bilayer stacking sequence. The structure is increasingly modulated with decreasing temperature by periodic displacements of the molecules along their long axes. An additional displacement of this type occurs at the $S_B-S_H$ transition.