Derivatives of 4-cyano-2,3-difluorophenol of the formula I ##STR1## wherein R.sup.1 is an alkyl group which has 1-12 C atoms and in which one or two CH.sub.2 groups can also be replaced by --O--, --CO--, --CO--O-- and/or --CH.dbd.CH--, no two 0 atoms being directly attached to one another,A.sup.1 and A.sup.2 independently of one another are each 1,4-phenylene which is unsubstituted or substituted by one or two F atoms, and in which one or two CH groups can also be replaced by N, or trans-1,4-cyclohexylene in which one or two non-adjacent CH.sub.2 groups can also be replaced by 0 atoms and/or S atoms,Z is --CO--O--, --O--CO--, --CH.sub.2 CH.sub.2 --, OCH.sub.2 --, --CH.sub.2 O, --C.tbd.C-- or a single bond,m is 0, 1 or 2 andQ is --CO-- or --CH.sub.2 --.