Propiolonitrile derivatives and liquid crystal compositions comprising the same

摘要

A propiolonitrile derivative of formula (I) wherein n1 and n2 each independently stand for 0 or 1; A1, A2 and A3 each independently represent a 1,4-phenylene, a 1,4-phenylene substituted by one or more fluorine atoms, a trans-1,4-cyclohexylene, a 1,3-dioxane-2,5-diyl or a 1,3-pyrimidine-2,5-diyl; Z1, Z2 and Z3 each independently represent a single bond, ethylene, ethenylene, ethynylene, carbonyloxy, oxycarbonyl, methyleneoxy, oxymethylene, 1,4-butylene or 1,4-butenylene; R represents a saturated, aliphatic hydrocarbyl radical of 1-10 carbons, an unsaturated, aliphatic hydrocarbyl radical of 2-10 carbons, a saturated or unsaturated, aliphatic hydrocarbyl radical of 1-10 carbons containing one or more ether linkages (-O-) in the chain and a saturated or unsaturated, fluoro-substituted aliphatic hydrocarbyl radical of 1-10 carbons containing one or more fluorine atoms in the chain; X1 and X2 each independently represent H, F or Cl; provided that at least one of X1 and X2 is F or Cl, when both n1 and n2 are 0, Z1 represents a single bond, ethylene, carbonyloxy or oxycarbonyl and R represents alkyl or alkoxy; or when n1 is 1, n2 is 1 or 0, Z1 and Z2 each independently represent a single bond or ethylene, Z3 represents ethylene and R represents alkyl or alkoxy. They have excellent properties as the ingredient of a liquid crystal composition, e.g. broad liquid crystal temperature range, high dielectric anisotropy and good compatibility with other liquid crystalline compounds, while keeping the properties of the composition such as low viscosity and being capable of providing high elastic constant ratio.