| abstract |
Pleochroic anthraquinone dyes of the formula (I) <IMAGE> in which W, X, Y and Z are hydrogen, NH2, OH, NHCH3 or NHC2H5, but not more than 3 of these substituents being identical to one another, R1 4 (R3) -phenyl if R2 is H, alkyl or alkoxy, each with up to 8 C atoms, CN or 4- (R3) -phenyl, and 4-alkylcyclohexyl or 4-alkoxyphenyl, if R2 is alkyl or alkoxy, each with up to 8 C atoms, and R3 is alkyl or alkoxy with up to 8 carbon atoms, in which the carbon chain is interrupted 1, 2 or 3 times by oxygen atoms which are not adjacent to one another, are suitable for doping liquid-crystalline dielectrics for electro-optical display elements based on the guest-host Effectively suitable. They have good dichroic ratio values and are sufficiently soluble in the common liquid-crystalline base materials. |