Fluorinated oxaanthracenes and their use in liquid-crystal mixtures

Compounds of the formula (I)

• where:
• X1 is H or F
• G1-G2 is —CH2—CH— or CH═C—
• R1, R2 are
• a) H
• b) the M2-A2-R5 moiety
• c) a straight-chain or branched alkyl radical having from 1 to 16 carbon atoms or a straight-chain or branched alkenyl radical having from 2 to 16 carbon atoms, in each of which
• c1) one or more nonadjacent and nonterminal CH2 groups may be replaced by —O—, —C(═O)O—, —O—C(═O)—, —O—C(═O)—O—, —C(═O)— or —Si(CH3)2— and/or
• c2) one CH2 group may be replaced by —C≡C—, cyclopropane-1,2-diyl, cyclobutane-1,3-diyl, cyclohexane-1,4-diyl or phenylene-1,4-diyl and/or
• c3) one or more hydrogen atoms may be replaced by F and/or Cl,
• R3 is
• a) H
• b) the M2-A2-R5 moiety
• c) a straight-chain or branched alkyl or alkyloxy radical having from 1 to 16 carbon atoms or a straight-chain or branched alkenyl or alkenyloxy radical having from 2 to 16 carbon atoms, in each of which
• c1) one or more nonadjacent and nonterminal CH2 groups may be replaced by —O—, —C(═O)O—, —O—C(═O)—, —O—C(═O)—O—, —C(═O)— or —Si(CH3)2— and/or
• c2) one CH2 group may be replaced by —C≡C—, cyclopropane-1,2-diyl, cyclobutane-1,3-diyl, cyclohexane-1,4-diyl or phenylene-1,4-diyl and/or
• c3) one or more hydrogen atoms may be replaced by F and/or Cl,
• R4 is
• a) H
• b) F, Cl, CN, —NCS, CF3, CHF2, CH2F, OCF3, OCHF2, OCH2F, OCH2CF3, OCH═CF2
• c) the M2-A2-R5 moiety
• d) a straight-chain or branched alkyl or alkyloxy radical having from 1 to 12 carbon atoms or a straight-chain or branched alkenyl or alkenyloxy radical having from 2 to 12 carbon atoms, in each of which
• d1) one or more nonadjacent and nonterminal CH2 groups may be replaced by —O—, —C(═O)O—, —O—C(═O)—, —O—C(═O)—O—, —C(═O)— or —Si(CH3)2— and/or
• d2) one CH2 group may be replaced by —C≡C—, cyclopropane-1,2-diyl or cyclobutane-1,3-diyl and/or
• d3) one or more hydrogen atoms may be replaced by F and/or Cl,
• M2 is —CO—O—, —O—CO—, —CH2—O—, —O—CH2—, —CF2—O—, —O—CF2—, —CH═CH—, —CF═CF—, —C≡C—, —CH2—CH2—CO—O—, —O—CO—CH2—CH2—, —CH2—CH2—, —CF2—CF2—, —(CH2)4—, —OC(═O)CF═CF— or a single bond
• A2 is 1,4-phenylene in which one or two hydrogen atoms may be replaced by F, Cl, CN and/or OCF3 or up to three hydrogen atoms may be replaced by fluorine, is 1,4-cyclohexylene in which one or two hydrogen atoms may be replaced by CH3 and/or F, is 1-cyclohexene-1,4-diyl in which one hydrogen atom may be replaced by CH3 or F or is 1,3-dioxane-2,5-diyl,
• R5 has the same possible definitions as R3 except -M2-A2-R5,
• with the provisos that
• a) when R2 is not H, R1 and R3 have to be H,
• b) when R2 is H, R4 must not have the definitions c) or d),
• c) R1, R2, R3 and R4 must not at the same time be H.