SmA-SmC-B₂ polymorphism in an achiral cyano substituted banana-shaped mesogen

Abstract

A new achiral five-ring banana-shaped mesogen is presented which has a cyano substituent in the 4-position of the central core. Microscopical, X-ray, dielectric and electro-optical investigations give evidence for the unusual phase sequence B2, SmC, SmA. The B2 phase shows an antiferroelectric switching behaviour; the spontaneous polarization was found to be 330 nCcm-2.