| 摘要 |
NEW MATERIAL:A liquid crystal compound of formula I (R, R' are 1-18C alkyl; X<1>, X<2> are direct bond, O, S, CidenticalC; A<1>, A<3> are 1,4-phenylene which may be substituted with one to four F or Cl atoms; Y<1>, Y<2> are CidenticalC, CH2CH2; A<2> is 1,4-phenylene, 2,5-pyridylene, 3,6-pyridazylene). USE:A smectic C liquid crystal compound. The compound of formula I has a low viscosity, excellent compatibility with other smectic C liquid crystal compounds, good orientation degree and good stability against light, heat and water. Useful as a component for changing the dielectric constant anisotropy of ferromagnetic liquid crystal compositions into negative anisotropy or as a component for widening the temperature range of the smectic C phase. PREPARATION:For example, a compound of formula: Y-A<1>-Y (Y is Cl, Br, I) is made to react with a compound of formula II in the presence of triethylamine and a 0- or 2-valent Pd catalyst in an inert gas atmosphere to prepare the compound of formula I (IV) wherein R=R': X<1>=X<2>; A<1> and A<3> are group of formula III; Y<1> and Y<2> are CidenticalC. |
