摘要 |
New 1,4-dioxanes of the formula I <IMAGE> I wherein R1 and R2 each signify and alkyl group with 1 - 10 C-atoms, wherein one or two CH2 groups can also be replaced by O-atoms, F, Cl, Br or CN, R2 also H, A1 and A2 each signify 1,4-phenylene, 1,4-cyclohexylene, 1,3-dioxane-2,5-diyl, 1,4-dioxane-2,5-diyl, peperidine-1,4-diyl, 1,4-bicyclo(2,2,2)-octylene or pyrimidine-2,5-diyl groups, unsubstituted or substituted by 1 - 4 F-atoms, Z1 and Z2 each signify -CO-O-, -O-CO-, CH2CH2-, OCH2- -CH2O- or a single bond, m and n each signify 0, 1, 2 or 3, (m+n), however, are at least 1 and at most 3, whereby for m=2 or 3, the groups A1 and for n=2 or 3 the groups A2 can each be the same or different from one another, as well as the acid-addition salts of the basic ones of these compounds, are suitable for use as components of liquid-crystalline dielectrics. |