| abstract |
Chiral dopants of the formula Iin which the variables have, independently of one another, the following meanings:A1 and A2a spacer with a chain length of 1 to 30 carbon atoms;Y1 to Y5a chemical bond, -O-, -S-, -C(=O)-, -C(=O)-O-, -O-C(=O)-, -CH=CH-C(=O)-O-, -O-C(=O)-O-, -C(=O)-N(R)- or -(R)N-C(=O)-, -CH2-O-, -O-CH2-, -CH=N-, -N=CH- or -N=N-;M a mesogenic group;R hydrogen, C1-C4-alkyl;Z1 and Z2hydrogen, C1-C4-alkyl, a polymerizable group or a radical having a polymerizable group;x a dianhydrohexitol residue selected from the group consisting of dianhydrosorbitol, dianhydromannitol and dianhydroiditol;m/n 0 or 1,where the radicals Z1, Z2, Y1 to Y5, A1 and A2 can be identical or different, and at least one Z1 or Z2 radical is a polymerizable group or a radical having a polymerizable group, and their use as chiral dopants for producing cholesteric liquid crystal compositions which can be employed as UV filters in cosmetic and pharmaceutical preparations. |