| 摘要 |
The invention relates to optically active compounds of the formula I <IMAGE> in which R is an alkyl or alkenyl radical having up to 15 carbon atoms which is unsubstituted, monosubstituted by -CN or at least monosubstituted by fluorine or chlorine, it also being possible for a CH2 group in these radicals to be replaced by -O-, -CO-, -O-CO-, -CO-O- or -O-CO-O-, A1 and A2 are each, independently of one another, a 1,4-phenylene radical, pyridine-2,5-diyl radical, pyrimidine-2,5-diyl radical, pyrazine-2,5-diyl radical, pyridazine-3,6-diyl radical, 1,3,4-thiadiazole-2,5-diyl radical, 1,2,4-thiadiazole-3,5-diyl radical or trans-1,4-cyclohexylene radical, each of which is unsubstituted or substituted by one or two fluorine atoms, and in which, in addition, one or two non-adjacent CH2 groups may be replaced by -O- and/or -S-, and/or a CH group, Z1, Z2 and Z3 are each, independently of one another, -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH2CH2-, -CH=CH-, -C 3BOND C- or a single bond, Q1 is -CH2CH2-, -CH2CH2CH2-, -OCH2-, -CH2OCH2-, -OCH2CH2-, -O-CO- or -CO-OCH2-, Q2 is -O-, -O-CO-, -(CH2)3-)- or a single bond, m is 0, 1, 2 or 3, n is 0 or 1, and o is 1 to 9, and the use thereof as components of liquid-crystalline phases.
|
