Properties of the liquid crystals formed by certain 2-p-alkoxybenzylideneamino-9,10-dihydrophenanthrenes

Abstract

The liquid crystal transition temperatures of 11 2-p-alkoxybenzylideneamino-9,10-dihydrophenanthrenes are reported and discussed. Graphical presentation shows a fall to a minimum followed by a rise to a maximum for the N–I transition temperatures of the early homologues and lack of convergence of the rising S_A–N and the falling N–I transition temperature curves for the higher homologues, i.e. there is persistence of nematic phases to a late stage in the homologous series. This behaviour is consistent with very low lateral cohesive forces operating throughout the homologous series.