Disclosed are liquid crystal compounds of formula IR.sup.1 --P--X--(A.sup.1 --Z.sup.1).sub.n --A.sup.2 --R.sup.2 IwhereinR is ##STR1## W is H, Cl or C.sub.1-5 -alkyl, and m is 1-7,P is C.sub.1-12 alkylene, one or more CH.sub.2 groups optionally being replaced by O,X is --O--, --S--, --COO--, --OCO-- or a single bond,R.sup.2 is C.sub.1-15 -alkyl optionally substituted by halogen, one or more CH.sub.2 groups optionally replaced by --O--, --S--, --CO--, --O--CO--, --CO--O-- or --O--CO--O--; R.sup.1 --P--X, CN, F, Cl or --V--Q--T,V is --O--, --S-- or a single bond,Q is --CH.sub.2 --, --CHF--, --CF.sub.2 --,T is F or Cl,n is 1 or 2,A.sup.1, A.sup.2 are 1,4-phenylene optionally substituted by F, Cl, CN or --W--C.sub.r H.sub.s F.sub.2r+1-s, or one of A.sup.1 or A.sup.2 is ##STR2## pyrimidine-2,5-diyl or pyrimidine-2,5 diyl, Z.sup.1 is --CO--O--, --O--CO--, --CH.sub.2 CH.sub.2 -- or a single bond,r is 1 or 2,s is O, 1, 2, 3, 4, or 5,W is a single bond, --O--, --S-- or --CO--,with the provisos (i) that at least one of A.sup.1 and A.sup.2 is a 1,4-phenylene group which is mono-or polysubstituted by Cl, CN or --W--C.sub.r H.sub.s F.sub.2r+1-s, said substituted 1,4-phenylene group optionally additionally substituted by one or more F-atoms, and (ii) that in case n=2 (a) only one of Z.sup.1 is --COO-- or --OCO-- or (b) at least one of A.sup.1 and A.sup.2 is double substituted or (c) at least two of A.sup.1 and A.sup.2 are substituted.