Abstract: A liquid crystal composition includes a host material comprising (a) two or more phenylpyrimidinyl compounds of general formula (I), wherein X1 and X2 are independently selected from the group consisting of straight or branched chain (C1-C12)alkyl, straight or branched chain (C1-C12)alkenyl and straight or branched chain (C1-C12)alkoxy, in which either or both of the alkyl, alkenyl or alkoxy groups may be substituted by one or more of halogen, oxygen and siloxane, and (b) at least one fluoroterphenyl compound of formula (II) or (III), wherein Y1 et Y2 are independently selected from the group consisting of straight or branched chain (C1-C12)alkyl, straight or branched chain (C1-C12)alkenyl and straight or branched chain (C1-C12)alkoxy, and wherein either or both of the alkyl, alkenyl or alkoxy groups may be substituted by one or more of halogen, oxygen and siloxane.

Abstract: An electroclinic device having two spaced cell walls each bearing electrode structures and treated on at least one facing surface with an alignment layer, a layer of a smectic liquid crystal material enclosed between the cell walls, where the liquid crystal material contains one or more of the compounds described by formula I as defined in the specification.

Abstract: An electroclinic device having two spaced cell walls each bearing electrode structures and treated on at least one facing surface with an alignment layer, a layer of a smectic liquid crystal material enclosed between the cell walls, where the liquid crystal material contains one or more of the compounds described by formula I as defined in the specification.

Abstract: An electoclinic device having two spaced cell walls each bearing electrode structures and treated on at least one facing surface with an alignment layer, a layer of a smectic liquid crystal material enclosed between the cell walls, where the liquid crystal material contains one or more of the compounds described by formula I as defined in the specification.

Abstract: The 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, ##STR1## where X may be CN, NO.sub.2, CF.sub.3, CF.sub.2 H, CFH.sub.2, halogen, hydrogen, alkyl or alkoxy; X.sub.2 may be CN, NO.sub.2, CF.sub.3, CF.sub.2 H, CFH.sub.2, halogen, hydrogen, alkyl or alkoxy; X.sub.3 may be CN, NO.sub.2, CF.sub.3, CF.sub.2 H, CFH.sub.2, halogen, alkyl, alkoxy or hydrogen; X.sub.4 may be CN, NO.sub.2, CF.sub.3, CF.sub.2 H, CFH.sub.2, halogen, alkyl, alkoxy or hydrogen; provided that at lease one of X or X.sub.2 is CF.sub.3, CF.sub.2 H, CFH.sub.2, CN, NO.sub.2 or halogen; A and B are independently phenyl, mono-fluorinated phenyl, di-fluorinated phenyl or cyclohexyl; Y may be single bond, COO, OOC, C.dbd.C; q may be 0 or 1; R.sub.1 may be an end group of formula (II) wherein Z may be a single bond, O, CO.sub.2, (CH.sub.2).sub.n or (CH.sub.2).sub.