Compounds for a liquid crystalline medium and use thereof for high frequency components

A compound of formula I*

• R1—(A1—Z1)m—A2—Z2A3pZ3—A4—(Z5—A5)n—R2 I*
• in which
• A1, A2, A3, A4, A5 each, independently of one another, denote
• a) 1,4-phenylene, in which one or more CH groups may be replaced by N, or a 2,6-naphthylene group of the formula
• b) a radical from the group thiophene-2,5-diyl, furan-2,5-diyl or a group of the formula
• or
• c) trans-1,4-cyclohexylene or cyclohexenylene, in which one or two non-adjacent CH2 groups may be replaced by —O— and/or —S—, and in which H may be replaced by F, 1,4-bicyclo[2.2.2]octylene, cyclobutane-1,3-diyl or spiro[3.3]heptane-2,6-diyl,
• and in which groups a), b) and c),
• one or more H atoms may also be substituted by a group as defined for L,
• where one or more of the groups A2, A3 and A4 denote a group of the formula
• and
• where the groups A2, A3 and A4 are substituted by a total of one or more groups L,
• L independently denotes branched or unbranched alkyl having 1 to 12 C atoms, alkenyl or alkynyl having 2 to 12 C atoms,
• in which in each case, independently of one another, one or more hydrogen atoms may be replaced by F or Cl and one or more —CH2— groups may be replaced by O, or denotes C3-C6 cycloalkyl or C3-C6 cycloalkenyl,
• F, Cl, Br, CN, NCS, SCN or SF5,
• Z2, Z3 independently denote —C≡C— or
• Y1, Y2, independently of one another, denote H, F, Cl, C1-C10 alkyl,
• Z1, Z5, independently of one another, denote a single bond, —C≡C—, —CH═CH—, —CH2O—, —(CO)O—, —CF2O—, —CF2CF2—, —CH2CF2—, —CH2CH2—, —(CH2)4—, —CH═CF— or —CF═CF—, where asymmetrical bridges may be oriented to both sides,
• R1 and R2, independently of one another, denote a halogenated or unsubstituted alkyl radical having 1 to 15 C atoms, where one or more CH2 groups in these radicals may each be replaced, independently of one another, by —C≡C—, —CH═CH—, —CF═CF—, —CF═CH—, —CH═CF—, —(CO)—, —S— or —O— in such a way that S or O atoms are not linked directly to one another,
• or denote F, Cl, Br, CN, CF3, OCF3 or SF5,
• R2 also denotes H,
• m, n, independently of one another, denote 0, 1 or 2, and
• p denotes 1 or 2.

A liquid-crystal medium, comprising a compound of formula I

• R1—(A1—Z1)m—A2—Z2A3pZ3—A4—(Z5—A5)n—R2 I
• in which
• A1, A2, A3, A4, A5 each, independently of one another, denote
• a) 1,4-phenylene, in which one or more CH groups may be replaced by N, or a 2,6-naphthylene group of the formula
• b) a radical from the group thiophene-2,5-diyl, furan-2,5-diyl or a group of the formula
• or
• c) trans-1,4-cyclohexylene or cyclohexenylene, in which one or two non-adjacent CH2 groups may be replaced by —O— and/or —S—, and in which H may be replaced by F, 1,4-bicyclo[2.2.2]octylene, cyclobutane-1,3-diyl or spiro[3.3]heptane-2,6-diyl,
• and in which groups a), b) and c),
• one or more H atoms may also be substituted by a group as defined for L,
• where one or more of the groups A2, A3 and A4 denote a group of the formula
• L independently denotes branched or unbranched alkyl having 1 to 12 C atoms, alkenyl or alkynyl having 2 to 12 C atoms,
• in which in each case, independently of one another, one or more hydrogen atoms may be replaced by F or Cl and one or more —CH2— groups may be replaced by O, or denotes C3-C6 cycloalkyl or C3-C6 cycloalkenyl,
• F, Cl, Br, CN, NCS, SCN or SF5,
• Z2, Z3 independently denote —C≡C— or
• Y1, Y2, independently of one another, denote H, F, Cl, C1-C10 alkyl,
• Z1, Z5, independently of one another, denote a single bond, —C≡C—, —CH═CH—, —CH2O—, —(CO)O—, —CF2O—, —CF2CF2—, —CH2CF2—, —CH2CH2—, —(CH2)4—, —CH═CF— or —CF═CF—, where asymmetrical bridges may be oriented to both sides,
• R1 and R2, independently of one another, denote a halogenated or unsubstituted alkyl radical having 1 to 15 C atoms, where one or more CH2 groups in these radicals may each be replaced, independently of one another, by —CH≡CH—, —CF═CF—, —CF═CF—, —CF═CH—, —CH═CF—, —(CO)—, —S— or —O— in such a way that S or O atoms are not linked directly to one another,
• or denote F, Cl, Br, CN, CF3, OCF3, —NCS or SF5,
• R2 also denotes H,
• m, n, independently of one another, denote 0, 1 or 2, and
• p denotes 1 or 2.