| abstract |
Chiral or achiral cyclic compounds of formula R?1-(A?1-Z?1)m?-A?2-Q?1-C*RCF3?-X, wherein R?1 denotes alkyl or perfluoralkyl which can be interrupted by O- and/or -CO- and/or -CO-O- and/or -CH=CH- and/or -CH halogen- and/or -CHCN- and/or -O-CO-CH halogen- and/or -CO-O-CHCN-, F, Cl, Br, CN or -Q?1-C*RCF3?-X; A?1 and A?2 denote unsubstituted 1,4-phenylene or 1,4-phenylene substituted with one or two F and/or CH3? and/or CN, wherein one or two CH groups can also be replaced by 1,4-cyclohexane, wherein one or two non-neighbouring CH2? groups can be replaced by O and/or S, 1-(4-) cyano-1,4-cyclohexylene, piperidin-1,4-diyl, 1,4-bicyclo(2,2,2)-octylen, 1,3,4-thiadiazol-2,5-diyl naphthalen-2,6-diyl, decahydronaphthalen-2,6-diyl or 1,2,3,4-tetrahydronaphthalene-2,6-diyl; Z?1 denotes -CO-O-, -O-CO-, -CH2?CH2?-, -OCH2?-, -CH2?O, -C=C-, or a single bond; X denotes H or CH3?; C* denotes a carbon atom bonded to four different substituents; or m = 1, 2 or 3; Q?1 denotes -O-, -O-CO-, -CO-O- or a single bond, and in the case in which at least one of the rings A?1 and A?2 is replaced by 1,4-phenylene substituted by one or two F atoms or A?1 is unsubstituted 1,4-phenylene, wherein one CH group is replaced by N, also denotes -O-(CH2?)n?-, -O-CO-(CH2?)n?- or -CO-O-(CH2?)n?, where n = 1, 2, 3 or 4; R is alkyl different from X, or, if Q is a single bond, alkoxy or alkanoyloxy. Said compounds can be used as chirally oriented smectic liquid crystal phases. |