The Effect of Trifluoromethyl and Difluoromethoxy Groups on Mesomorphic Properties

Abstract

This paper describes the effect of terminal substituent on the mesomorphic properties in 3-and 4-(4-alkoxyphenoxycarbonyl)phenyl 3- and 4-R-benzoate and 4-(4-alkoxybenzoyloxy)phenyl 2-, 3-, and 4-R-benzoates (R = CF₃, OCF₃, OCF₂H). The meta-trifluoromethoxy and para-difluoromethoxy compounds tend to show a smectic C phase, as well as smectic A and nematic ones, and introduction of a chiral carbon in the alkoxyl group induces the chiral smectic C one.

Key Words:

• liquid crystals
• thermal property
• Sm C
• chiral Sm C
• substituent effect
• fluorophilic effect