Enaminoketone mesogens having polar terminal groups

Abstract

Abstract Homologous series of 4″-nitro- and 4″-cyano- derivatives of 1-(4′-alkoxyphenylamino)-3-phenyl-1-propen-3-onesandastructurally similar seriesofl-(4′-alkoxyphenylamino)-3-(4″-pyridyl-N-oxide)-1-propen-3-ones were synthesized and studied by DSC and optical methods. The compounds behave typically for strongly polar mesogens: the smectic Ad phase exists above a critical chain length and the reentrant nematic phase is observed in the vicinity of the critical double point. For pyridyl N-oxides, a second-order SmAd - SmCd phase transition line is observed.