| abstract |
The invention relates to electro-optical liquid crystal compositions of a liquid crystal mixture of a compound of formula I wherein-independently of one another is trans-1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-3-fluoro-1 , 4-phenylene, and one of A1 i, and for the present, A2, also pyridine-2,5-diyl, pyrimidine-2,5-diyl, 1,3-dioxane-2,5-diyl, tetrahydropyran-2, 5-diyl or naphthalene-2,6-diyl, Z1 and Z2 independently of one another are a single bond, -CH2-CH2 -, -COO-, -OCO-, -C = C-, CH2O- or combinations of these bridging groups , Y and X independently of one another denote H or F, one of X and Y also Cl, W -CN, -Cl, -F, -CF3, -OCF3, OCHF2, NCS or R2, R1 and R2 independently of one another alkyl having 1-12 C atoms, where also one or 2 non-adjacent CH2- groups can be replaced by -O- or -CH = CH-, am is o, 1 or 2. |