HETEROCYCLIC COMPOUNDS AS COMPONENTS OF LIQUID CRYSTAL PHASES

摘要

Heterocyclic compounds of the formula Iec R<1>-A<1>-A<2>-CH2CH2-A<3>-R<2> in which R<1> and R<2> in each case independently of one another represent an alkyl group having 1-15 C atoms in which one or two non-adjacent CH2 groups can also be replaced by O atoms and/or -CO- groups and/or -O-CO- groups and/or -CO-O- groups and/or -O-COO- groups and/or -CHCN- and/or -CH-halogen- groups, and one of the radicals R<1> and R<2> can also be F, Cl, Br or CN, A<1>, A<2> and A<3> in each case independently of one another are a 1,4-cyclohexylene group which is unsubstituted or mono- or polysubstituted by F and/or Cl atoms and/or CH3 and/or CN groups and in which one or two non-adjacent CH2 groups can also be replaced by O atoms and/or S atoms, or are a 1,4-bicyclo-(2.2.2)-octylene group or are a 1,4-phenylene group which is unsubstituted or monosubstituted or polysubstituted by F and/or Cl atoms and/or CH3 and/or CN groups and in which one or more CH groups can also be replaced by N, with the proviso that at least one of the groups A<1> and A<2> is a pyrazine-2,5-diyl group (Pa) or a pyridine-2,5-diyl group (Py).