Liquid Crystalline Properties of 3,4-Di-and 2,4-Di(4-alkoxybenzoyloxy)-benzylidene-4-alkoxyanilines

Abstract

This paper describes liquid crystalline properties for some homologs of 3,4-di-(1) and 2,4-di(4-alkoxybenzoyloxy)benzylidene-4-alkoxyanilines (2) and some related compounds. Compounds 1 tend to show a nematic phase with a notable cybotactic with a layer structure and also a smectic C phase when the alkoxyl groups are suitably long. Compounds 2 show only a monotropic nematic phase, and the nematic-isotropic transition temperatures show a notable even-odd effect even in the higher homologs. The smectic C phase was further characterized by X-ray examination, and the liquid crystalline properties are discussed in terms of the molecular structure characteristic.

Key Words:

• Synthesis
• thermal properties
• lateral substituent
• X-ray examination
• cybotactic
• molecular structure