Ethane derivatives

Abstract

Ethane derivatives of the formula I R.sup.1 --A.sup.1 --CH.sub.2 CH.sub.2 --A.sup.2 --(A.sup.3).sub.n --R.sup.2 I wherein R.sup.1 is H, an alkyl group with 1-12 C atoms, in which one or two non adjacent CH.sub.2 groups can also be replaced by O atoms and/or CO groups and/or --O--CO-- groups and/or --CO--O groups, F, Cl, Br or R.sup.3 --A.sup.4 --Z.sup.1 --, R.sup.2 is --CN or --Z.sup.2 --A.sup.4 --CN, A.sup.1 is --A--, --A--A.sup.5 -- or --A.sup.5 --A--, A.sup.2 is an 1,4-phenylene group which is unsubstituted or substituted by one or two F and/or Cl atoms and/or CH.sub.3 groups and/or CN groups and in which one or two CH groups can also be replaced by N atoms, A is a 1,4-cyclohexylene group, in which one or two non adjacent CH.sub.2 groups can also be replaced by O atoms, or is a 1,3-dithiane-2,5-diyl group or 1,4-bicyclo(2,2,2)-octylene group, A.sup.3, A.sub.4 are each a 1,4-cyclohexylene group, in which one or two non adjacent CH.sub.2 groups can also be replaced by O atoms, or are each a 1,3-dithiane-2,5-diyl group, and A.sup.5 or a 1,4-phenylene group which is unsubstituted or substituted by one or two F and/or Cl atoms and/or CH.sub.3 groups and/or CN groups, and in which one or two CH groups can also be replaced by N atoms, n is 0 or 1, Z.sup.1 is --CO--O--, --O--CO--, --CH.sub.2 CH.sub.2 --, --CH.sub.2 O--, --OCH.sub.2 or a single bond, Z.sup.2 is --CH.sub.2 CH.sub.2 --, --CH.sub.2 O--, --OCH.sub.2 --, --O--CO-- or a single bond and R.sup.3 is H or an alkyl group with 1-12 C atoms, in which one or two non adjacent CH.sub.2 groups can also be replaced by O atoms and/or CO groups and/or --CO--O-- groups and/or --O--CO-- groups, with the proviso that (a) if A.sup.2 =A.sup.3 =1,4-phenylene (n=1) and/or if R.sup.1 -A.sup.1 =p-(trans-4-alkylcyclohexyl)-phenyl, at least one of the groups A.sup.2 and/or A.sup.3 is laterally substituted, and (b) if A.sup.1 =A and/or R.sup.1 -A.sup.1 =trans-4-(trans-4-alkylcyclohexyl)-cyclohexyl, n is 1, can be used as components of liquid crystal phases.

Dependencies are inferred from the claim text.