Synthesis and properties of new three-ring phenylacetylene liquid crystals containing the cyclohexyl unit

Two series of new three-ring phenylacetylene liquid crystals were synthesized and their physical properties were evaluated. These liquid crystal materials show only a nematic phase, high clearing points and good solubilities. The compounds containing two cyclohexyl rings exhibit moderate birefringence (Δn) values of around 0.14, while those containing one cyclohexyl ring show a broad nematic phase range and high Δn of around 0.33.