Patent ID: 7282246

Claim:
A compound of the formula (I) in which R 1 , R 3 are each independently a) H b) one of R 1 and R 3 is —M 1 —A 1 —R 5 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 which c1) one or more nonadjacent and nonterminal CH 2 groups may be replaced by —O—, —C(═O)O—, —O—C(═O)—, —O—C(═O)—O—, —C(═O)— or —Si(CH 3 ) 2 — and/or c2) one CH 2 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 d) F, Cl, CF 3 , OCF 3 , OCF 2 H R 2 , R 4 are each independently a) H b) one of R 2 and R 4 is —M 1 —A 1 —R 5 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 which c1) one or more nonadjacent and nonterminal CH 2 groups may be replaced by —O—, —C(═O)O—, —O—C(═O)—, —O—C(═O)—O—, —C(═O)— or —Si(CH 3 ) 2 — and/or c2) one CH 2 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 X 1 , X 2 are each independently H or F M 1 is —CO—O—, —O—CO—, —CH 2 —O—, —O—CH 2 —, —CF 2 —O—, —O—CF 2 —, —CH═CH—, —CF═CF—, —C≡C—, —CH 2 —CH 2 —CO—O—, —O—CO—CH 2 —CH 2 —, —CH 2 —CH 2 —, —CF 2 —CF 2 —, —(CH 2 ) 4 —, —OC(═O)CF═CF— or a single bond A 1 is 1,4-phenylene in which one or two hydrogen atoms may be replaced by F, Cl, CN and/or OCF 3 or three hydrogen atoms may be replaced by fluorine, 1,4-cyclohexylene in which one or two hydrogen atoms may be replaced by CH 3 and/or F, 1-cyclohexene-1,4-diyl in which one hydrogen atom may be replaced by CH 3 or F, or 1,3-dioxane-2,5-diyl and R 5 has the same possible definitions as specified for R 2 and R 4 , with the exception of —M 1 —A 1 —R 5 , but independently of the particular definitions of R 2 and R 4 with the following provisos: 1) at least one of X 1 , X 2 has to be F 2) R 1 , R 2 , R 3 and R 4 must not at the same time be H 3) at most two of R 1 , R 2 , R 3 , and R 4 are c).