Mesophases Induced in the Binary Systems Consisting of the 4-Dimethylamino-4-Alkoxy and 4-Nitro-4-Alkoxy Derivatives of N-Benzylideneaniline

Abstract

Abstract The effect of terminal alkoxyl group on the induction of mesophases has been examined by preparing phase diagrams for binary systems of potentially mesogenic 4-dimethylamino and 4-nitro derivatives of N-benzylideneaniline. All the systems composed of the methoxy and ethoxy derivatives produce a nematic phase, while both a nematic and a smectic phases are found when at least one of the component compounds carries a propoxyl group. The only exception is N-[(4-dimethylamino)benzylidene]-4-ethoxyaniline-N-(4-nitrobenzylidene)-4-propoxyaniline system which exhibits a smectic phase alone. The maximum temperature of the nematic-isotropic transition point curve is not very sensitive to the exchange in the positions of the terminal groups, especially those in the donor molecules. On the other hand, the thermal stabilities of the induced smectic phase and solid complex are markedly affected by the positions of the terminal groups.