New alkoxy, alkenoxy ethoxy and poly:ethoxy benzene cpds. for cells - useful in liq. crystal medium, esp. in dielectric for electro=optical display with wide mesophase range and favourable optical anisotropy and low temp. properties e.g. solubility

摘要

New 4-substd.-1-alk(en)oxy (poly)ethoxy benzene derivs. are of formula (I): R1 = H, 1-15C alk(en)yl, opt. with one CN or CF3 substit. or halogen substit(s)., in which -CH2- gp(s). may be replaced by -O-, -S-, 1,3-cyclo butylene, -CO-, -CO-O-, -O-CO- or -O-CO-O- and O-atoms are not attached to one another directly; R2 = 1-15C alk(en)yl, opt. with halogen substit(s).; A1-2 = (a) trans-1,4-cyclohexylene (Cyc), in which non-adjacent -CH2- gp(s). may be replaced by -O- and/or -S-; (b) 1,4-phenylene (Phe), in which one or two CH gps. may be replaced by N; or (c) 1,4-cyclohexenylene, 1,4-bicyclo(2,2,2) -octylene, piperidin-1,4-diyl, naphth-2,6-diyl, decahydro naphth-2,6-diyl or 1,2,3,4-tetrahydro naphth-2,6-diyl; gps. (a) and (b) may be substd. by CN or F; Z1-3 = -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH2CH2-, -CH=CH-, -C=C- or a single bond; and one of Z1-3 may also be -(CH2)4- or -CH=CH-CH2CH2-; L1-4 = H or F, and L1-4(s) = F; m = 0, 1 or 2; n = 0 or 1; and r = 1-7. (I) may be prepd. by standard prepn., e.g. as in Houben-Weyl, Methoden der Organischen Chemie, Georg-Thieme-Verlag, Stuttgart, vol. IX, p. 867 ff. Examples are given in the text (below). Specifically n = 0, Z3 = a single bond, L3 = F and (A1-Z1)m-A2-Z2- = -Cyc-, -Phe-, -Cyc-Z1-Cyc-, -Cyc-Z1-Phe-; or n = 0, Z3 = a single bond and (A1-Z2)m-A2Z2- = -Cyc-Z1-(2F,3F-Phe)- with (2F,3F-Phe) = 2,3-difluoro-1,4-phenylene. USE/ADVANTAGE - (I) are used in liq. crystal (LC) media, which are used in LCDs and as dielectric in electrooptical displays (claimed). They are esp. useful in twisted, esp. TN and STN cells and may also be used in displays based on the guest-host, deformation aligned phase or dynamic scattering effect. (I) are stable LC or mesogenic cpds. and combine relatively low viscosity with relatively high dielectric anisotropy and high nematogenicity. The LC media have a wide mesophase range, favourable optical and dielectric anisotropy and improved low temp. properties, e.g. solubility in the usual LC materials, whilst the formation of smectic phases is suppressed.