摘要：

Fluoromethyl ketones of the formula I ##STR1## are suitable as components of liquid-crystalline media wherein R is H, a substituted or unsubstituted alkyl or alkenyl radical having 1 to 15 carbon atoms, A 1 and A 2 are each, independently of one another, a (a) trans-1,4-cyclohexylene radicals and derivatives thereof in which, in addition, one or more non-adjacent CH 2 groups is optionally replaced by --O-- and/or --S--, (b) 1,4-phenylene radicals and derivatives thereof in which, in addition, one or two CH groups is optionally replaced by N, or (c) radical from the group consisting of 1,4-cyclohexenylene, 1,4-bicyclo(2,2,2)octylene, piperidine-1,4-diyl, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl and 1,2,3,4-tetrahydronaphthalene-2,6-diyl, wherein radicals (a) and (b) are optionally substituted by one or two fluorine atoms, Z 1 and Z 2 are each, independently of one another, --CO--O--, --O--CO--, --CH 2 O--, --OCH 2 --, --CH 2 CH 2 --, --CHCH--, --C.tbd.C-- or a single bond, and one of the radicals Z 1 and Z 2 is optionally --(CH 2 ) 4 -- or --CHCH--CH 2 CH 2 --, X is H, F or Cl and is 0, 1 or 2.

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