Azotolane liquid-crystalline polymers: Huge change in birefringence by photoinduced alignment change

Novel liquid-crystalline polymers (LCPs) containing a long azotolane moiety were synthesized, and the relationship between the chemical structures and the photoresponsive behavior was investigated. All homogeneously aligned LCP films exhibited extremely high values of birefringence (Δn) in the wide wavelength range. Specifically, the azotolane LCP with two azobenzene units showed the most efficient change in the alignment of the azotolane moiety with a huge change in Δn (≥0.65). This means that the high value of Δn in the homogeneously aligned state can be converted to the change in Δn effectively. Copyright © 2006 American Chemical Society.