Electrooptical Chromophores for Nonlinear Optical and Photorefractive Applications

Transient photoconductivity in a discotic hexagonal plastic crystal

Photoconductivity in the columnar phases of a glassy discotic twin

Liquid-crystalline copolymers with covalently attached dichroic dyes were synthesized and characterized. Copolymers with high anthraquinone and trisazo-dye content were obtained by copolymerization of dye monomers with 4-cyanophenyl 4-(6-acryloyloxyhexyloxy)benzoate (1) and 6-acryloyloxyhexyl 4-(trans-4-propylcyclohexyl)benzoate (2). Particular attention is given to the influence of the dye content and the dye structure on the liquid-crystalline behavior of the copolymers.

Electronic Properties of Discotic LC-Materials

Abstract We have made extensive studies of the charge-carrier mobilities in the discotic hexagonal mesophases of triphenylene-based discotic liquid crystals. Using the time-of-flight technique, transient photocurrents were measured yielding charge-carrier mobilities for various electric fields and temperatures. Starting from promising results obtained with the monomeric discotic liquid crystalline model compound hexapentyloxytriphenylene (H5T), we synthesized a “discotic twin” with two triphenylene units linked together by a suitable spacer. Additionally, we synthesized a discotic liquid crystalline oligomer consisting of four triphenylene units which are bound to a flexible cyclosiloxane r…