| abstract |
Abstract Biphenylylethanes of the formula I I in which one of the radicals R1 and R2 is X and the other radical R1 or R2 is R-Y- where X is H, halogen, -CF3, -OCHF2, -OCF3, -CN, -NCS or - NO2, R is alkyl, fluoroalkyl, alkenyl or oxaalkyl and Y is O, S, -CO-O-, -O-CO-, -O-CO-O-, a single bond or - in the case where m = 1 - alternatively trans-1,4-cyclohexylene or , m is 1 or 2, Ph is in each case identical or different radicals selected from the group comprising 1,4-phenylene, 2-fluoro-1,4-phenylene, 3-fluoro-1,4-phenylene and 3,5-difluoro-1,4-phenylene, L3 and L4 are each H, or one of these radicals is alter-natively F, L1, L2 and L5 are each H or F, with the proviso that in the case where X = CN or R1 = -NCS, Y is trans-1,4- cyclohexylene or and/or m = 2 and/or one of the radicals L1, L2 and L3 is fluorine and/or Ph-CN is 2-fluoro-4-cyanophenyl or 3,5-difluoro-4-cyanophenyl, are suitable as components of liquid-crystalline phases. |