Effect of molecular structure of chiral fluorinated compounds on spontaneous polarization of ferroelectric liquid crystals

The trans and cis isomers derived from chiral 1-trifluoromethyl-3-phenyl-2-propen-1-ol were prepared as chiral dopants of ferroelectric liquid crystals. They were doped to an achiral compound possessing a smectic C phase, and the induced spontaneous polarization of the mixtures was investigated. The observed spontaneous polarization for the trans isomer is larger than that for the cis isomer. The signs and values of spontaneous polarization were explained by a model which examined the fitness of two typical conformers possessing positive and negative spontaneous polarization to the zigzag conformation of molecules in the smectic C phase.