Chiral or achiral cyclic compounds of formula (I): R?1-(A?1-Z?1)m?-A?2-Q?1-C*RX-Q?2-(A?3-Z?2)n?-(A?4)o?-R?2, in which R?1 and R?2, independently of one another, represent an alkyl or perfluoralkyl group with 1 to 12 C atoms, in which also one or two non-adjacent CH2? or CF2? groups can be replaced by O atoms and/or -CO- groups and/or -CO-O- groups and/or -CH=CH- groups and/or -CHhalogen- and/or -CHCN- groups and/or -O-CO-CHhalogen- and/or -CO-O-CHCN- groups; one of the groups R?1 and R?2 also represents H, F, Cl, Br or CN, R?1 is also -Q?1-C*RX-Q?2-R?2, whereby Q?1, R, X, Q?2 and R?2 have the same notations; A?1, A?2, A?3 and A?4, independently of each other, represent an unsubstituted 1,4 phenylene or substituted by one or two F and/or Cl atoms and/or CH3? groups and/or CN groups, wherein also one or two CH groups can be replaced by N; 1,4-cyclohexylene, wherein also one or two non-adjacent CH2? groups can be replaced by O atoms and/or S atoms; piperidine-1,4-diyl, 1,4-bicyclo(2,2,2)octylene-, 1,3,4-thiadiazol-2,5-diyl, naphthalene-2,6-diyl-, decahydronaphthalene-2,6-diyl- or 1,2,3,4-tetrahydronaphthalene-2,6-diyl-; Z?1 and Z?2 are individually -CO-O-, -O-CO-, -CH2?CH2?-, -OCH2?-, -CH2?O-, -C=C- or a simple bond; X is halogen, CN or CH3?, R is an alkyl group different from X (and where n= o= 0 also from R?2); C* is a carbon atom combined with four different substituents; m and n each, independently of one another, are 0, 1, 2 or 3; o is 0 or 1; (m + n + o) is 1, 2, 3 or 4; and Q?1 and Q?2, each independently of one another, are alkylene with 1 to 4 C atoms, where also a CH2? group can be replaced by -O-, -S-, -CO-, -O-CO-, -CO-O-, -S-CO-, -CO-S-, -CH=CH-COO-, -CH=CH-, -CHhalogen- and/or -CHCN-, or a simple bond. These compounds can be used as constituents of chirally tilted smectic liquid crystal phases.
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