| abstract |
Compounds of formula (I) may be used as alignment layers in liquid crystal devices wherein X1-5 are idependently selected from H, F, CN, phenylene, C1-10 alkyl, whereby when X1 = X2, then X1,2 = H and when X3 = X4, then X3,4 = H, S1-3 are spacer units, PG1-3 are photoisomerisable/dimerisable groups. |