| abstract |
A compound is of formula (I), in which: A 1 to A 4 , E 1 and E 2 each independently represent hydrogen or an optionally-substituted hydrocarbon group; B 1 and B 2 each independently represent a single bond, an oxygen atom or an optionally-substituted hydrocarbon group; MG 1 and MG 2 each independently represent an optionally-substituted ring system; CG is a divalent or polyvalent chiral group. The optically active compound may be used as a doping agent for liquid crystals for a wide range of applications including solid state cholesteric filters for projection displays, circular polarisers, optical filters, etc. |