Liquid crystalline mixtures containing compounds of the formula ##STR1## wherein n stands for the number 0 or 1; X.sup.1 and X.sup.2 denote single covalent bonds or one of the symbols X.sup.1 and X.sup.2 also denotes --COO--, --OOC-- or --CH.sub.2 CH.sub.2 --; the rings A.sup.1, A.sup.2, and A.sup.3 represent 1,4-phenylene, 2-fluoro-1,4-phenylene or trans-1,4-cyclohexylene or one of these rings also represents a 2,5-disubstituted pyrimidine ring or a trans-2,5-disubstituted m-dioxane ring; R.sup.1 signifies 4-alkenyl or on a cyclohexyl ring also 2Z-alkenyl; and R.sup.2 denotes alkyl, alkoxy, --CN or --NCS, as well as the manufacture of these compounds and the use for electro-optical purposes are described.
                            含有以下式子的液晶混合物:##STR1## 其中n代表数字0或1;X.sup.1和X.sup.2表示单个共价键或其中一个符号X.sup.1和X.sup.2还表示--COO--,--OOC--或--CH.sub.2 CH.sub.2--;环A.sup.1,A.sup.2和A.sup.3表示1,4-苯撑,2-
氟-1,4-苯撑或反-1,4-环己撑或其中一个环还表示2,5-二取代
嘧啶环或反-2,5-二取代m-
二噁烷环;R.sup.1表示4-烯基或在环己基环上也可以是2Z-烯基;R.sup.2表示烷基,烷氧基,--CN或--
NCS,以及这些化合物的制造和用于电光目的的使用。