title: Photoinduced polarization inversion in a ferroelectric liquid crystal using an ambidextrous chiral thioindigo dopant.
abstract: In this Communication, we report the first example of photoswitching of a ferroelectric SmC* liquid crystal based on a photoinduced sign inversion of the spontaneous polarization (PS) induced by a single chiral dopant. This is achieved without concomitant destabilization of the SmC* phase using the "ambidextrous" dopant 6-((R,R)-2,3-difluorooct-1-yloxy)-5'-nitro-6'-((R)-2-octyloxy)thioindigo. The (R)-2-octyloxy side chain is sterically coupled to the thioindigo core via the nitro substituent and induces a positive polarization, whereas the (R,R)-2,3-difluorooct-1-yloxy side chain is decoupled from the core and induces a negative polarization. With this new design, the increase in transverse dipole moment of the thioindigo core upon trans-cis photoisomerization raises the polarization power of the coupled 2-octyloxy/thioindigo unit above that of the 2,3-difluorooctyloxy unit and inverts the net sign of PS.
authors.affiliation: Department of Chemistry, Chernoff Hall, Queen's University, Kingston, Ontario, Canada K7L 3N6.
authors.forename: Jason Z
authors.initials: JZ
authors.lastname: Vlahakis
authors.forename: Michael D
authors.initials: MD
authors.lastname: Wand
authors.forename: Robert P
authors.initials: RP
authors.lastname: Lemieux