Abstract
Four series of fluorinated tolanes, naphthylphenylacetylenes and naphthylphenyldiacetylenes were prepared and characterized. Most of the fluorinated tolanes exhibit no mesomorphic behaviour. However, most of the fluorinated naphthylphenylacetylenes and naphthylphenyldiacetylenes form enantiotropic nematic phases. The dielectric anisotropy and birefringence of some selected compounds were measured by a guest-host method. All of those studied show relatively high dielectric anisotropy and birefringence.