| abstract |
Novel optically-active cpds. of formula (I) are claimed as are also multi-component chiral smectic liq. crystal compsns. contg. (I) and L.C. displays using the compsn. as the dielectric. In (I), R = up to 15C alk(en)yl opt. substd. by one CN or by at least one F or Cl; the alk(en)yl gp. opt. also being interrupted by one -O-, -CO-, -O.CO-, -CO.O-, or -O.CO.O-gp.; A1 and A2 = the following gps. opt. substd. by one or two F atoms: 1,4-phenylene, pyridin-2,5-diyl, pyrimidin-2,5 diyl, pyrazin-2,5-diyl, pyridazin-3,6-diyl, 1,3,4-thiadiazol -2,5-diyl, 1,2,4-thiadiazol-3,5-diyl, trans-1,4-cyclohexylene (opt. with 1 or 2 neighbouring CH2 gps. replaced by -O- and/or -S-, and/or with one CH gp. replaced by -C(CN)-), 1,4-cyclohexylene, 1,4-bi-cyclo(2,2,2)-octylene or piperidin-1,4-diyl; Z1-Z3 = a bond, -CO.O-, -O.CO-. -CH2O-, -OCH2-, -CH2CH2-, -CH=CH- or -CC-; X = H or F; Q = -OCH2-, -COOCH2 or -CH2OCH2-; p = 1-12; and one or both m and n = 0 and the other is 0 or 1; with the proviso that when Q = -OCH2- or -COOCH2-; , |