| abstract |
The invention concerns compounds of general formula (I) Z-Y-A-(Y-M)n-Y1-X-Y1-(M-Y)¿n?-A-Y-Z in which the groups A, independently of one another, are spacers, n is 1, 2 or 3, X is a group of formula (a), (b), (c), (d), (e), (f), (g) or (h), the groups Y?1¿, independently of one another, designate O, OCO, OCOO, or a direct bond, the groups Y, independently of one another, designate O, S, CO, COO, OCO, OCOO, CONR, NRCO or a direct bond, R is hydrogen or a C¿1?-C4 alkyl, the groups M, independently of one another, designate an aliphatic, aromatic, heteroaliphatic or heteroaromatic ring system optionally substituted by chlorine, bromine, fluorine, iodine, cyan or methyl, and the groups Z, independently of one another, designate hydrogen or a polymerizable group. These compounds are suitable for use in electro-optical display elements, as chiral doping substances for nematic or cholesteric liquid crystals for producing coloured reflective layers or pigments disposed cholesterically by liquid crystals. |