| 摘要 |
Nitrogen-containing heterocyclic compounds of the formula I RI-(A-Z)n-A-R2 I wherein R1 and R2 in each case independently of one another are alkyl group with 1-15 C atoms, wherein one or two non-adjacent CH2 groups can also be replaced by 0 atoms and/or -CO- group and/or -O-CO- groups and/or -CO-O- groups, and one of the radicals R1 and R2 can also be H, CN, F, Cl or Br, the groups A in each case independently of one another are a 1,4-phenylene group, wherein one or two CH groups can also be replaced by N atoms, a 1,4-cyclohexylene group, wherein one or two CH2 groups which are not adjacent can be replaced by 0 atoms, a 1,3-dithiane-2,5-diyl group, a 1,4-bicyclo(2,2,2)-octylene group, a decahydronapthalene-2,6-diyl group or a 1,2,3,4-tetrahydronaphthalene-2,6-diyl group, the group Z in each case independently of one another are -CO-O-, -O-CO-, -CH2CH2-, -OCH2-, -CH2O- or a single bond and n is 3 or 4, with the proviso that (a) at least one of the groups A is a "1,4" phenylene group, wherein two CH groups are replaced by N atoms, and (b) at least one of the other groups A contains a cycloaliphatic radical and/or at least one group Z is not a single bond, can be used as components of liquid crystal phases. |
