New partly fluorinated uncondensed poly:cyclic cpds. - useful in LCD medium, having low viscosity and wide mesophase range

摘要

New partly fluorinated polycyclic cpds. (I) are of the formula: R1-A1-Z1-(A2-Z2)M-A3-(Y)n-Q-X (I); A1, A2 and A3 independently = (a) trans-1,4-cyclohexylene, in which one or more non-adjacent CH2 gps. may be replaced by -O-and/or -S-; (b) 1,4-phenylene, in which 1 or 2 CH gps. may be replaced by N; (c) a 1,3-cyclobutylene, 1,3-bicyclo(1,1,1)pentylene, 1,4-cyclohexenylene, 1,4-bicyclo(2,2,2) octylene, piperidin-1,4-diyl, naphtha-2,6-diyl, decahydronaphtha-2,6-diyl or 1,2,3,4-tetrahydronaphtha-2,6-diyl gp.; and the (a) and (b) gps. may be substd. by CN or halogen; R1 = 1-15C (alk(en)yl, opt. substd. by CN, halogen, or CF3, in which one or more CH2 gps. may be replaced by -S-, -O-, -CO-, -CO-O-, -O-CO- or -O-CO-O- but -S-and/or -O- atoms are not linked directly; Z1 and Z2 independently = -CH2CH2-, -CC-, -CH2O-, -OCH2-, -CO-O-, -O-CO-, -CH=N-, -N=CH-, -CH2S-, -SCH2-, a single bond or 3-6C alkylene, in which one CH2 gp. may be replaced by -O-, -CO-O-, -O-CO-, -CH(halogen)- or -CH(CN)-; Y = O, S, CO, CO-O or O-CO; Q = (CFH)o-(CF2)r-(CFH)p; X = CN, F, Cl or NCS; m = 0, 1 or 2; n = 0 or 1; r = 0 or 1; if X = CN, Cl or NCS, may also = 2; o and p = 0 or 1; (o+p+r) = 2 or 3. (I) can be prepd. (not claimed) by standard methods, e.g. as described in Houben-Weyl, Methoden der Organischen Chemie, Georg-Thieme-Verlag, Stuttgart. USE/ADVANTAGE - (I) are claimed for use as components of liquid crystalline media for electrooptical displays, which are claimed for use esp. in matrix LCDs. They are esp. useful in media for active matrix displays or supertwist dispalys. (I) with suitable reactive gps. may also be used in the prodn. of liquid crystalline polymers and polycondensates. (I) are stable liquid crystalline or mesogenic cpds. and give media with a wide mesophase range, relatively low visocisty and advantageous optical and dielectric anisotropy, with medium positive dielectric anisotropy.