申请人:Hoechst Aktiengesellschaft
公开号:US05702638A1
公开(公告)日:1997-12-30
Phenanthridine derivatives, and their use in liquid-crystalline mixtures A ferroelectric liquid-crystal mixture containing one or more phenanthridine derivatives of the formula (I) ##STR1## E.sup.1 and E.sup.2 are identical or different and are --N--, --CF-- or --CH--; R.sup.1 and R.sup.2 are identical or different and are, for example, a straight-chain or branched alkyl radical having 1 to 20 carbon atoms; Q is --CH.sub.2 --O--, --CO--O-- or a single bond; M.sup.1 and M.sup.2 are identical or different and are --CO--O--, --O--CO--, --CH.sub.2 --O--, --O--CH.sub.2 --, --CH.sub.2 --CH.sub.2 --, --C.tbd.C--, or a single bond; A.sup.1 and A.sup.2 are identical or different and are 1,4-phenylene, in which one or more H atoms may be replaced by F, trans-1,4-cyclohexylene, pyrimidine-2,5-diyl, pyridine-2,5-diyl, where one H atom may be replaced by F, 1,3,4-thiadiazole-2,5-diyl, 1,3-dioxane-2,5-diyl, 1,3-dithiane-2,5-diyl, 1,3-thiazole-2,4-diyl, 1,3-thiazole-2,5-diyl, thiophene-2,4-diyl or thiophene-2,5-diyl; m and n are zero or one, but their sum is at most one. Even addition of only small amounts of phenanthridine derivatives of the formula (I) gives ferroelectric liquid-crystal mixtures having high negative values for the dielectric anisotropy.
苯并咪唑衍生物及其在液晶混合物中的应用。一种铁电液晶混合物,其中包含一个或多个公式(I)的苯并咪唑衍生物:
##STR1##
其中,E.sup.1和E.sup.2相同或不同,是--N--,--CF--或--CH--;R.sup.1和R.sup.2相同或不同,例如是直链或支链烷基,具有1至20个碳原子;Q是--CH.sub.2--O--,--CO--O--或单键;M.sup.1和M.sup.2相同或不同,是--CO--O--,--O--CO--,--CH.sub.2--O--,--O--CH.sub.2--,--CH.sub.2--CH.sub.2--,--C.tbd.C--或单键;A.sup.1和A.sup.2相同或不同,是1,4-苯撑基,其中一个或多个H原子可能被F取代,反-1,4-环己撑基,嘧啶-2,5-二基,吡啶-2,5-二基,其中一个H原子可能被F取代,1,3,4-噻二唑-2,5-二基,1,3-二氧杂环戊烷-2,5-二基,1,3-二硫杂环戊烷-2,5-二基,1,3-噻唑-2,4-二基,1,3-噻唑-2,5-二基,噻吩-2,4-二基或噻吩-2,5-二基;m和n为零或一,但它们的和最多为一。即使仅添加少量公式(I)的苯并咪唑衍生物,也可以得到具有高负介电各向异性值的铁电液晶混合物。