| 摘要 |
Cyclohexane derivatives of formula I R1-(A1)m-Z1-A-Z2-(A2)n-R2 I wherein R1 and R2 are each H, an alkyl group which has 1-10 C atoms and in which one or two CH2 groups can also be replaced by O atoms, F, CL, Br, CN or -O-COR, A1 and A2 are each 1,4-phenylene, 1,4-cyclohexylene, 1,3-dioxane-2,5-diyl, piperidine-1,4-diyl, 1,4-bicyclo(2,2,2)-octylene or pyrimidine-2,5-diyl groups which are unsubstituted or substituted by 1-4 F atoms, A is a 1,4-cyclohexylene group which is substituted in the 1-position and/or 4-position by alkyl, alkoxy, fluorinated alkyl or fluorinated alkoxy, each of which has 1-5 C atoms, F, Cl, Br and/or CN and which can also carry 1 or 2 further F, Cl or Br atoms and/or CN groups, Z1 and Z2 are each -CO-O-, -O-CO-, -CH2CH2-, -OCH2-, -CH2O- or a single bond, R is an alkyl group which has 1-5 C atoms, m is 1 or 2 and n is 0 or 1, it being possible, where m=2, for the two groups A1 to be identical or different from one another; and the acid addition salts of those compounds which are basic, are suitable for use as components of liquid-crystal dielectrics. |
