Novel liquid crystal mixtures
AssigneeHoffmann-La Roche Inc.
InventorsMartin Petrzilka, Martin Schadt
Life of this patent
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Abstract
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.
Claims10
A compound of the formula ##STR15## wherein n is the integer 0 or 1;
- X.sup.1 and X.sup.2 are single covalent bonds or one of the X.sup.1 and X.sup.2 also is --COO--, --OOC-- or --CH.sub.2 CH.sub.2 --;
- the rings A.sup.1, A.sup.2 and A.sup.3 independently are 1,4-phenylene, 2-fluoro-1,4-phenylene or trans-1,4-cyclohexylene or one of these rings also is a 2,5-disubstituted pyrimidine or trans-2,5-disubstituted m-dioxane;
- R.sup.1 is 4-alkenyl or when positioned on a cyclohexyl ring R.sup.1 also can be 2Z-alkenyl;
- and R.sup.2 is alkyl, alkoxy, --CN or --NCS;
- with the proviso that simultaneously R.sup.1 is not 4-pentenyl, ring A.sup.1 is not trans-1,4-cyclohexylene, X.sup.1 is not --CH.sub.2 CH.sub.2 --, ring A.sup.2 is not 1,4-phenylene, n is not the integer 0 and R.sup.2 is not --CN.
A compound of the formula ##STR16## wherein X.sup.3 and X.sup.4 are single covalent bonds or one of X.sup.3 and X.sup.4 also can be --CH.sub.2 CH.sub.2 --;
- rings A.sup.4, A.sup.5 and A.sup.6 independently are 1,4-phenylene, 2-fluoro-1,4-phenylene or trans-1,4-cyclohexylene;
- R.sup.4 is hydrogen or alkyl;
- n is the integer 0 or 1;
- and R.sup.1 is 4-alkenyl or when positioned on a cyclohexyl ring R.sup.1 also can be 2Z-alkenyl.
Dependencies are inferred from the claim text.