4(4-Alkyloxybenzoyloxy)-4' -cyanoazobenzole: Eine homologe Reihe flüssigkristalliner Verbindungen mit der ungewöhnlichen Phasenfolge smektisch A-nematisch-smektisch A / 4(4-Alkyloxybenzoyloxy)-4'-cyanoazobenzenes: A Homologous Series of Liquid Crystals Exhibiting the Unusual Phase Sequence Smectic A -Nematic -Smectic A

Abstract

The synthesis and the phase transition temperatures of homologous liquid crystalline 4(4-alkyloxybenzoyloxy)-4'-cyanoazobenzenes with alkyl chain length n = 1-12 and n = 16 are reported. All compounds exhibit smectic A phases; the SA phase region being interrupted by a "re-entrant" nematic phase for alkyl chain lengath n ≥ 9.