Influence of Polar Endgroups on Mesomorphic Behavior of Symmetric Smectogens

Abstract

This paper describes the thermotropic polymorphic behavior of a set of new compounds carrying a variety of Y endgroups:

with Y = HOOC‒, CH₃OCO‒, CH₃CH₂CO‒, and CH₃NHCO‒. Of these compounds only the ester derivative proved capable of producing liquid crystals in the pure state. The absence of mesomorphic behavior in the other derivatives is due to the high thermal stability of the crystalline phases, as shown by a systematic study of their binary mixtures with the previously reported Y˭NC–compound.

Key Words:

• polar mesogens
• mixtures
• polymorphism