Ferroelectric columnar liquid crystals realized by introducing chiral alkyl groupsasymmetrically

Abstract

We have reported that an N,N’-diphenylurea compound with six chiral side chains exhibits ferroelectric columnar liquid crystals. In this study, we investigated whether generation of the ferroelectricity is due to the formation of a helical structure or tight fitting of the side chains. Asymmetric urea compounds which have (1) three (S)-citronellyl and three decyl groups, (2) three (S)- and three (R)-citronellyl groups, and (3) three and two (S)-citronellyl groups, on the left and right phenyl groups, were evaluated. Because ferroelectricity was demonstrated regardless of the helical structure formation, indicating that the ferroelectricity is also achieved by the intermolecular forces enhanced by the tight fitting of the substituents.