Ring compounds

摘要

Compounds of the formula R1-Q1-(CH2)m-(COO)n-(CH2)p-Q2-R2 wherein R1 and R2 are each independently alkyl or alkoxy each of 1-12 C atoms, F, Cl, Br, CN or -Q3-R3, or one of R1 and R2 can also be H; Q1, Q2 and Q3 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; R3 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 Q3 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 R1 to R3 is F, Cl or Br or none of R1 to R3 is CN or two of the radicals R1 to R3 are CN, are valuable liquid crystalline components.