| abstract |
Compounds have formula (I), in which R1 and R2 represent independently of each other R, OR, OCOR, COOR or OCOOR, R represents an alkyl group with 1-15 C atoms, wherein one or more non-adjacent CH2 groups, not linked to O, can be substituted with -O-, -CO-, -O-CO-, -CO-O-, -CH halogen, -CHCN- and/or -CH=CH-, A1, A2 represent independently of each other 1,4-phenylene and A3 or trans-1,4-cyclohexylene, m, n and o represent each 0 or 1, m+n+o equal to 0, 1 or 2, Z1 and Z2 represent independently of each other -CH2-O-, -OCH2-, -CH2CH2- or a simple bond and X represents F, Cl, Br, J or CN. These compounds can be used in the conditions described under claim 1 as components of ferro-electric liquid crystal phases. |