The Effect of a Long Alkoxyl Group on the Mesomorphic Properties of 4-(4-Alkoxyphenoxycarbonyl)phenyl 3-Alkoxy-4-cyanobenzoates

Abstract

This paper describes syntheses and properties of some members of 4-(4-alkoxyphenoxycarbonyl)phenyl 3-alkoxy-4-cyanobenzoates. The ethoxy and propoxy groups at the adjacent position of the cyano one are unfavorable for the formation of a smectic A phase and the long alkoxy groups such as butoxy, pentyloxy, and hexyloxy ones facilitate the formation of a smectic C phase. The characterization and molecular arrangement of the smectic C phase were made by a differential scanning calorimeter, microscopic observation, and small-angle X-ray diffraction examination, and the roles of the alkoxyl group at the adjacent position of the cyano group on the mesomorphic properties are discussed.

Key Words:

• Synthesis
• thermal properties
• lateral alkoxy group
• polar liquid crystals
• X-ray diffraction