Preparation and Properties of C 2-Symmetric Organic Radical Compounds Showing Ferroelectric Liquid Crystal Properties

Abstract

We have synthesized a new class of liquid crystalline (LC) organic radical compounds 2, which are the C2-symmetric derivatives of the previously reported compounds 1 containing a chiral nitroxide unit and an ester group in the mesogen core, and their LC properties have been fully characterized. The enantiomerically enriched 2 showed N* and SmC* phases. Their LC phase transition behavior is similar to that of 1, whereas the ferroelectric properties of the SmC* phase of (2S,5S)-2 differed from those of (2S,5S)-1. We discuss the origin of this difference in terms of their molecular structures optimized by molecular orbital calculations.