Organic materials for a liquid crystal device.

摘要

A material suitable for a guest-host liquid crystal device comprises a solution of a liquid crystal material and a pleochroic dye wherein the pleochroic dye comprises at least one anthraquinone compound free from water solubilising and ionic substituents and having the formula: <CHEM> wherein: P is OH or NH2; each group X<A> is independently selected from OH, NO2, SR and NZ1Z2 provided that one group X<A> is SR and the other group X<A> is OH, NO2, or NZ1Z2; m is 1 or 2; each group Q1 is independently alkyl; each group R is independently selected from optionally substituted alkyl, aryl and cyclohexyl groups; each of the groups Z1 and Z2 is independently selected from hydrogen, and optionally substituted alkyl, aryl and cycloalkyl groups.