| abstract |
PCT No. PCT/GB95/00018 Sec. 371 Date Jul. 10, 1996 Sec. 102(e) Date Jul. 10, 1996 PCT Filed Jan. 6, 1995 PCT Pub. No. WO95/18848 PCT Pub. Date Jul. 13, 1995The invention describes liquid crystal compounds of formula (I) which are suitable for use in liquid crystal devices including those devices which exploit the electroclinic effect, <IMAGE> (I) <IMAGE> (II) where X may be CN, NO2, CF3, CF2H, CFH2, halogen, hydrogen, alkyl or alkoxy; X2 may be CN, NO2, CF3, CF2H, CFH2, halogen, hydrogen, alkyl or alkoxy; X3 may be CN, NO2, CF3, CF2H, CFH2, halogen, alkyl, alkoxy or hydrogen; X4 may be CN, NO2, CF3, CF2H, CFH2, halogen, alkyl, alkoxy or hydrogen; provided that at lease one of X or X2 is CF3, CF2H, CFH2, CN, NO2 or halogen; A and B are independently phenyl, mono-fluorinated phenyl, di-fluorinated phenyl or cyclohexyl; Y may be single bond, COO, OOC, C=C; q may be 0 or 1; R1 may be an end group of formula (II) wherein Z may be a single bond, O, CO2, (CH2)n or (CH2)nO where n may be 1 or 2; J and M may be independently H, C1-4 alkyl; W may be C1-C12 straight or branched alkyl chain; R2 may contain 1-14 carbon atoms wherein one or more non-adjacent CH2 groups may be replaced by CO2 or O. X or X2 may give rise to steric hindrance with the nearest terminal group. The materials of the current invention may be mixed together and/or with other liquid crystal compounds. Suitable devices which the materials of the present invention may be incorporated in include beam steerers, piezoelectric actuators or sensors and pyroelectric sensors and displays in general. The materials of the present invention may also be useful as dopants in ferroelectrics and as second order non-linear optic materials for second harmonic conversion of light. |