New low viscosity, fluorine-contg. liq. crystal cpds. - useful in liq. crystal mixts. for electro=optical display devices and exhibit stable LC mixts having wide mesophase ranges

摘要

F-contg. cpds. of formula (I) are new. In (I), R is H or 1-15C alkyl or alkenyl opt. substd. once by CN or CF3 or at least once by halogen and opt. with one or more CH2 replaced by -O-, -S-, 1,3-cyclobutylene, -CO-, -CO.O-, -O.CO- or -O.CO.O- such that O atoms are not directly bonded to each other; ring A is 1,4-cyclohexylene or 2L1, 6L2-phenylene-1,4 where the 1-position in linked to the OCF2.C(+X1X2 gp.; L1 and L2 are indep. H, F or Cl; A1 and A2 are (a); (b) or (c) where (a) and (b) can be substd. once or twice by F; (a) trans-1,4-cyclohexylene with one or more non-adjacent CH2 gps. opt. replaced by -O- and/or -S-; (b) 1,4-phenylene with one or two CH gps. opt. replaced by N; (c) 1,4-cyclohexenylene, 1,4-bicyclo2,2,2octylene, piperidin-1,4-diyl, naphthalen-2,6-diyl, decahydronaphthalen-2,6-diyl, or 1,2,3,4-tetrahydronaphthalen-2,6-diyl; Z1 and Z2 are independently -CO.O-, -O.CO-, -CH2O-, -OCH2-, -CH2CH2-, -CH=CH-, -CC- or a single bond, or one of Z1 and Z2 can also be -(CH2)4- or -CH=CH.CH2CH2-; m is 0, 1 or 2; X1 is F or Cl; and X2 is Cl, CF3, OCF3 or OCHF2. USE/ADVANTAGE - The use is claimed of (I) as a component in liq. crystal media, such media being used in liq. crystal or electro-optical display devices. (I) combine low viscosity with relatively high dielectric anisotropy and give stable liq. crystal mixts. with wide mesophase ranges and good low temp. properties.