Liquid-crystalline compounds

摘要

Liquid-crystalline compounds of the formula I <IMAGE> I R is H, an alkyl or alkylene radical, Z1 and Z are each, independently of one another, -CH2CH2-, -CH=CH-,-C 3BOND C- or a single bond, and one of the radicals Z1 and Z is alternatively -(CH2)4- or -CH=CH-CH2CH2-, A is trans-1,4-cyclohexylene in which, in addition, one or two non-adjacent CH2 groups may be replaced by -O-, A1 is trans-1,4-cyclohexylene in which, in addition, one or two non-adjacent CH2 groups may be replaced by -O-, or is 1,4-phenylene which is unsubstituted or monosubstituted or disubstituted by fluorine and/or Cl atoms and in which, in addition, one or two CH groups may be replaced by N, W is -O-, Q is a single bond, m, o, s, r and t are as defined below, Y is F, Cl, OCF3, CHF2, OCHF2 or OCHF, and can be CF3, are suitable as components for liquid-crystalline media.