Abstract: Compounds of the formulaR.sup.1 --Q.sup.1 --(CH.sub.2).sub.m --(COO).sub.n --(CH.sub.2).sub.p --Q.sup.2 --R.sup.2whereinR.sup.1 and R.sup.2 are each independently alkyl or alkoxy each of 1-12 C atoms, F, Cl, Br, CN or --Q.sup.3 --R.sup.3, or one of R.sup.1 and R.sup.2 can also be H;Q.sup.1, Q.sup.2 and Q.sup.3 are each independently 1,4-phenylene, 1,4-cyclohexylene, 1,4-bicyclo(2,2,2)-octylene or 1,3-dioxane-2,5-diyl, each of which is unsubstituted or substituted by 1-4 fluorine, chlorine or bromine atoms;R.sup.3 is alkyl or alkoxy each of 1-8 C atoms, H, F, Cl, Br or CN;m is 1, 2, 3, 4, 5 or 6; n is 0 or 1; and p is 0, 1, 2, 3, 4 or 5; the sum of (m+p) being 2, 4 or 6 and the sum of (m+n+p) being at least 3;but with the proviso that Q.sup.3 is unsubstituted 1,4-phenylene or 1,4-phenylene substituted by a fluorine, chlorine or bromine atom, only when n=1 or (m+p)=6 or at least one of R.sup.1 to R.sup.3 is F, Cl or Br or none of R.sup.1 to R.sup.3 is CN or two of the radicals R.sup.1 to R.sup.

Abstract: A novel liquid crystal compound has a formula: ##STR1## where: ##STR2## is a trans-2,5-disubstituted-1,3-dioxan ring or a 2,5-disubstituted-1,3-pyrimidine ring ##STR3## is a 1,4-disubstituted benzene ring optionally containing one or more F, Cl or CH.sub.3 groups as lateral substituents; R.sub.1 is an alkyl group; andX is a terminal group selected from H, CN, Cl, F and R.sub.2 where R.sub.2 is selected from alkyl R.sub.3, alkoxy OR.sub.3, alkylcarbonyloxy OCOR.sub.3 and alkoxycarbonyloxy OCOOR.sub.3.

Abstract: Compounds of the formulaR.sup.1 --Q.sup.1 --(CH.sub.2).sub.m --(COO).sub.n --(CH.sub.2).sub.p --Q.sup.2 --R.sup.2whereinR.sup.1 and R.sup.2 are each independently alkyl or alkoxy each of 1-12 C atoms, F, Cl, Br, CN or --Q.sup.3 --R.sup.3, or one of R.sup.1 and R.sup.2 can also be H;Q.sup.1, Q.sup.2 and Q.sup.3 are each independently 1,4-phenylene, 1,4-cyclohexylene, 1,4-bicyclo(2,2,2)-octylene or 1,3-dioxane-2,5-diyl, each of which is unsubstituted or substituted by 1-4 fluorine, chlorine or bromine atoms;R.sup.3 is alkyl or alkoxy each of 1-8 C atoms, H, F, Cl, Br or CN;m is 1, 2, 3, 4, 5 or 6; n is 0 or 1; and p is 0, 1, 2, 3, 4 or 5; the sum of (m+p) being 2, 4 or 6 and the sum of (m+n+p) being at least 3;but with the proviso that Q.sup.3 is unsubstituted 1,4-phenylene or 1,4-phenylene substituted by a fluorine, chlorine or bromine atom, only when n=1 or (m+p)=6 or at least one of R.sup.1 or R.sup.3 is F, Cl or Br or none of R.sup.1 to R.sup.3 is CN or two of the radicals R.sup.1 to R.sup.

Abstract: A novel liquid crystal compound has a formula: ##STR1## where: ##STR2## is a trans-2,5-disubstituted-1,3-dioxan ring or a 2,5-disubstituted-1,3-imidine ring ##STR3## is a 1,4-disubstituted benzene ring optionally containing one or more F, Cl or CH.sub.3 groups as lateral substituents; R.sub.1 is an alkyl group; andX is a terminal group selected from H, CN, Cl, F and R.sub.2 where R.sub.2 is selected from alkyl R.sub.3, alkoxy OR.sub.3, alkylcarbonyloxy OCOR.sub.3 and alkoxycarbonyloxy OCOOR.sub.3.