The unclassified smectic phase of N-(4-n-pentyloxybenzylidene)-4-n-hexylaniline (50.6)

Abstract

For many years, N-(4-n-pentyloxybenzylidene)-4-n-hexylaniline (50.6) has been known to exhibit an unclassified smectic phase. This phase has been shown to occur between a smectic B and a smectic G phase, and the transitions to and from the phase on both heating and cooling have been shown to be truly reversible. The nature of the unclassified phase has now been investigated fully, and we have shown that it has the classification-smectic F. Therefore, 50.6 exhibits the sequence (1) of enantiotropic phases : N, SA, SC, SB, SF, SG and the last three phases in this sequence show a change from an ordered to a less ordered to a more ordered smectic phase with temperature change