Liquid crystal compounds having a terminal alkoxy propenyl group

A liquid crystalline mixture with at least two components, wherein at least one component is a compound of the formula ##STR13## wherein rings A.sup.1 and A.sup.2 each independently are unsubstituted or halogen-substituted 1,4-phenylene, pyridin-2,5-diyl, pyrimidin-2,5-diyl, pyrazin-2,5-diyl or trans-1,4-cyclohexylene or trans-1,3-dioxane;

• n is 0 or 1;
• Z.sup.1 and Z.sup.2 each independently are a single covalent bond or --CH.sub.2 CH.sub.2 --, --COO--, --OOC--, --OCH.sub.2 --, --CH.sub.2 O--, --(CH.sub.2).sub.4 --, --O(CH.sub.2).sub.3 --, --(CH.sub.2).sub.3 O--, the trans form of --O--CH.sub.2 --CH.dbd.CH--, --CH.dbd.CH--CH.sub.2 --O--, --(CH.sub.2).sub.2 CH.dbd.CH-- or --CH.dbd.CH--(CH.sub.2).sub.2 --;
• R.sup.1 is an alkyl group of 1 to 12 carbon atoms;
• R.sup.2 is halogen, cyano, or trifluoroacetyl, or R.sup.2 is alkyl, alkoxy, alkenyl, alkenyloxy, alkoxyalkyl, alkoxyalkoxy, alkenyloxyalkyl, alkenyloxyalkoxy, alkyloxyalkenyl or alkyloxyalkenyloxy each of such R.sup.2 moieties being unsubstituted or fluorine substituted.

A electro-optical cell comprising:

• (a) two plate means;
• (b) liquid crystal means disposed between the two plate means and including a compound of the formula:
• ##STR14## wherein rings A.sup.1 and A.sup.2 each independently are unsubstituted or halogen-substituted 1,4-phenylene, pyridin-2,5-diyl, pyrimidin-2,5-diyl, pyrazin-2,5-diyl or trans-1,4-cyclohexylene or trans-1,3-dioxane;
• n is 0 or 1;
• Z.sup.1 and Z.sup.2 each independently are a single covalent bond or --CH.sub.2 CH.sub.2 --, --COO--, --OOC--, --OCH.sub.2 --, --CH.sub.2 O--, --(CH.sub.2).sub.4 --, --O(CH.sub.2).sub.3 --, --(CH.sub.2).sub.3 O--, the trans form of --O--CH.sub.2 --CH.dbd.CH--, --CH.dbd.CH--CH.sub.2 --O--, --(CH.sub.2).sub.2 CH.dbd.CH-- or --CH.dbd.CH--(CH.sub.2).sub.2 --;
• R.sup.1 is an alkyl group of 1 to 12 carbon atoms;
• R.sup.2 is halogen, cyano, or trifluoroacetyl, or R.sup.2 is alkyl, alkoxy, alkenyl, alkenyloxy, alkoxyalkyl, alkoxyalkoxy, alkenyloxyalkyl, alkenyloxyalkoxy, alkyloxyalkenyl or alkyloxyalkenyloxy, each of such R.sup.2 moieties being unsubstituted or fluorine substituted;
• and
• (c) means for applying electric potential to said plate means.