| 摘要 |
New fluorinated 5-ring cpds. R1-(A1-Z1)m-A2-Z2-W (I) where W = a condensed ring system of formula (IIA), (IIB) or (IIC). A3 = a cyclohexane, cyclohexene or phenyl ring; Q = C=O, CHF, CF2, CHR2 or CFR2; Q' = CF or CR2; R2 = 1-15C (fluoro)alkyl; Y1 = O or S; Y2 = O, CO, C=O or CHnF2-n; or, if Q = C=O, CHF or CF2, Y2 may also = CHR2 or CFR1; n = 0, 1 or 2; Y3 = N, CH or CF; or, if Q' = CF, Y3 may also = CR2; X = H, F or Cl; R1 = H or 1-15C alk(en)yl, which may have one CN or CF3 substit. or at least one halogen substit. and/or one or more CH2 gps. replaced by -O-, -S-, -CO-, a 1,3-cyclobutane ring, -CO-O-, -O-CO- or -O-CO-O-, so that hetero-atoms are not linked directly; A1 and A2 = (a) trans-1,4-cyclohexylne, in which one or more non-adjacent CH2 gps. may be replaced by -O- and/or -S-; (b) 1,4-phenylene in which one or two CH gps. may be replaced by N; or (c) a 1,4-cyclohexenylene, 1,4-bicyclo(2,2,2) -octylene, piperidin-1,4-diyl, naphthalene-2,6-diyl, decahydronaphthalene -2,6-diyl or 1,2,3,4-tetrahydro naphthalene -2,6-diyl; in which the (a) and (b) gps. may be substd. by CN, Cl orF; Z1 and Z2 = -CO-O-, -O-CO-, -CH2O-, -O-CH2-, -CH2CH2-, -CH=CH-, -C=C- or a single bond; m = 0, 1 or 2; at least one of Y2, Y3, Q and Q' has F substit(s). USE/ADVANTAGE - (I) are used in liquid crystal (LC) media, which are used esp. in LCDs and as dielectric in electrooptical displays (claimed). (I) are LC or mesogenic cpds., which have good chemical, thermal and photo-stability, and are esp. suitable for TFT and STN displays. They give stable media and the thermal stability required for a high holding ratio.
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