Synthesis and Study of Novel Liquid Crystalline Homologous Series: 4-(4'-n-Alkoxy Benzoyloxy)-3-Methoxy Phenyl azo-3', 4' Dichlorobenzenes

摘要

The synthesis and mesomorphic properties of a new homologous series of azomesogens, 4-(4'-n-alkoxy benzoyloxy)-3-methoxy phenyl azo-3",4" dichlorobenzene is detailed. The first four members of the series are nonmesomorphic, and the other eight members are smectogenic in character. The smectic mesophase, which is exhibited montropically, commences from the pentyl to the hexadecyl derivatives. The usual odd-even effect is observed in the isotropic-smectic transition curve. The isotropic-smectic transition curve behaves in a normal manner. The smectic mesophase shows a focal conic fan shaped texture of the smectic A type. An important feature of the series is the absence of the nematic property. The thermal stability and mesomorphic characteristic are compared with two structurally similar homologous series.