Compound of formula I in which R 11, R 21 and R 22 each, identically or differently, denote, F, Cl, Br, I, CN, SCN, OH, SF 5, straight chain or branched alkyl with up to 15 C atoms which may be unsubstituted, mono- or polysubstituted by F, Cl, Br, I or CN, it being also possible for one or more non-adjacent CH 2 groups to be replaced, in each case independently of one another, by or -O-, -S-, -NH-, -C -, -C O-, -OC -, -OC O-, -S-C -, -CO-S-, -CH=CH- or -C≡C- in such a manner that O and/or S atoms are not linked directly to one another, A 11, A 12 A 21 and A 22 each, independently of one another, denote a radical selected from the following groups: a) the group consisting of trans-1,4-cyclohexylene, 1,4-cyclohexenylene, and decaline-2,6-diyl, in which one or more non-adjacent CH 2 groups may be replaced by -O- and/or -S- and in which one or more H atoms may be replaced by F, b) the group consisting of 1,4-phenylene and 2,6-naphthylene, in which one or two CH groups may be replaced by N and in which, in addition, one or more H atoms may be replaced by L, c) the group consisting of 1,3-dioxane-2,5-diyl, tetrahydrofuran-2,5-diyl, cyclobutane-1,3-diyl, thiophene-2,5-diyl, selenophene-2,5-diyl, and 1,2,3,4-tetrahydronanaphthaline-2,6-diyl, each of which may be mono- or polysubstituted by L, d) the group consisting of bicyclo[1.1,1]pentane-1,3-diyl, bicyclo[2.2.2]octane-1,4-diyl, and spiro[3.3]heptane-2,6-diyl, in which one or more H atoms may be replaced by F L each, identically or differently, denote halogen, cyano, alkyl, alkoxy, alkylcarbonyl or alkoxycarbonyl group with 1 to 7 C atoms, wherein one or more H atoms may be substituted by F or Cl, Z 11 and Z 12 independently of one another, denote a single bond, -CF 2 O-, -OCF 2 -, -CH 2 CH 2 -, -CF 2 CF 2 -, -C O-, -OC -, -CH 2 O-, -OCH 2 -, -CF=CH-, -CH=CF-, -CF=CF-, -CH=CH- or -C≡C-, preferably -CH 2 CH 2 -, -CF 2 CF 2 -, -CH=CH- or a single bond, Y denotes F, m and n are, independently of one another, 0, 1 or 2, with the proviso that at least one of m and n denotes 0, p and q are, independently of one another, 0 or 1, where at least one of p and q is 0. R 11, R 21 and R 22 each, identically or differently, denote, F, Cl, Br, I, CN, SCN, OH, SF 5, straight chain or branched alkyl with up to 15 C atoms which may be unsubstituted, mono- or polysubstituted by F, Cl, Br, I or CN, it being also possible for one or more non-adjacent CH 2 groups to be replaced, in each case independently of one another, by or -O-, -S-, -NH-, -C -, -C O-, -OC -, -OC O-, -S-C -, -CO-S-, -CH=CH- or -C≡C- in such a manner that O and/or S atoms are not linked directly to one another, A 11, A 12 A 21 and A 22 each, independently of one another, denote a radical selected from the following groups: a) the group consisting of trans-1,4-cyclohexylene, 1,4-cyclohexenylene, and decaline-2,6-diyl, in which one or more non-adjacent CH 2 groups may be replaced by -O- and/or -S- and in which one or more H atoms may be replaced by F, b) the group consisting of 1,4-phenylene and 2,6-naphthylene, in which one or two CH groups may be replaced by N and in which, in addition, one or more H atoms may be replaced by L, c) the group consisting of 1,3-dioxane-2,5-diyl, tetrahydrofuran-2,5-diyl, cyclobutane-1,3-diyl, thiophene-2,5-diyl, selenophene-2,5-diyl, and 1,2,3,4-tetrahydronanaphthaline-2,6-diyl, each of which may be mono- or polysubstituted by L, d) the group consisting of bicyclo[1.1,1]pentane-1,3-diyl, bicyclo[2.2.2]octane-1,4-diyl, and spiro[3.3]heptane-2,6-diyl, in which one or more H atoms may be replaced by F a) the group consisting of trans-1,4-cyclohexylene, 1,4-cyclohexenylene, and decaline-2,6-diyl, in which one or more non-adjacent CH 2 groups may be replaced by -O- and/or -S- and in which one or more H atoms may be replaced by F, b) the group consisting of 1,4-phenylene and 2,6-naphthylene, in which one or two CH groups may be replaced by N and in which, in addition, one or more H atoms may be replaced by L, c) the group consisting of 1,3-dioxane-2,5-diyl, tetrahydrofuran-2,5-diyl, cyclobutane-1,3-diyl, thiophene-2,5-diyl, selenophene-2,5-diyl, and 1,2,3,4-tetrahydronanaphthaline-2,6-diyl, each of which may be mono- or polysubstituted by L, d) the group consisting of bicyclo[1.1,1]pentane-1,3-diyl, bicyclo[2.2.2]octane-1,4-diyl, and spiro[3.3]heptane-2,6-diyl, in which one or more H atoms may be replaced by F L each, identically or differently, denote halogen, cyano, alkyl, alkoxy, alkylcarbonyl or alkoxycarbonyl group with 1 to 7 C atoms, wherein one or more H atoms may be substituted by F or Cl, Z 11 and Z 12 independently of one another, denote a single bond, -CF 2 O-, -OCF 2 -, -CH 2 CH 2 -, -CF 2 CF 2 -, -C O-, -OC -, -CH 2 O-, -OCH 2 -, -CF=CH-, -CH=CF-, -CF=CF-, -CH=CH- or -C≡C-, preferably -CH 2 CH 2 -, -CF 2 CF 2 -, -CH=CH- or a single bond, Y denotes F, m and n are, independently of one another, 0, 1 or 2, with the proviso that at least one of m and n denotes 0, p and q are, independently of one another, 0 or 1, where at least one of p and q is 0.