| abstract |
New linear polycyclic benzene derivs. are of formula (I). In the formula, R1, R2 = halogen, CN, CNS or Q-Y; Q = -O-, -S- or a single bond; Y = mono- or polyhalo-(1-12C)-alk(en)yl; A1 and A2 = unsubstd. or mono- or polyfluoro-1,4-phenylene, in which 1 or 2 CH gps. may be replaced by N; or A2 = trans-1,4-cyclohexylene, in which 1 or more non-adjacent CH2 gps. may be replaced by -O- and/or -S-; one of Z1 and Z2 = a single bond and the other -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH2CH2-, -CH=CH-, -CC-, -(CH2)4-, -CH=CH-CH2CH2- or a single bond; L1, L2 = H or F; m = 1 or 2; and one or both of L1 and L2 = Fe if R2 = Q-Y with Q = a single bond and Y = mono-fluoro-alkenyl.(I) is pref. of formula (IA), (IB), (IC), or (ID). |