Amphiphilic dyes for NLO in LB-films

The influence of structural variations of phenyl-hydrazones and stilbazium salts on monolayer behaviour and second-harmonic generation in LB-monolayers is discussed. In contrast to the stilbazium salts the variation of the substituents of the phenylhydrazones does not influence the absorption maximum of the dyes in resonance enhancement of the nonlinearity. This allows a direct comparison of the substitution pattern on SHG.

Transient photoconductivity in a discotic hexagonal plastic crystal

Molecular Recognition-Induced Function and Competitive Replacement by Hydrogen-Bonding Interactions:  Amphiphilic Barbituric Acid Derivatives, 2,4,6-Triaminopyrimidine, and Related Structures at the Air−Water Interface

The phenomenon of molecular recognition inducing further function is common in nature. However, there are few synthetic systems which achieve this cascade type mechanism, and those are generally ca...

Photoconductivity in the columnar phases of a glassy discotic twin

ChemInform Abstract: Amphiphilic Dyes for Nonlinear Optics: Dependence of Second Harmonic Generation on Functional Group Substitution.

Mixed polymeric monolayers and Langmuir-Blodgett multilayers with functional low molecular weight guest compounds

Abstract Mixed monolayers and Langmuir-Blodgett multilayers of functional low molecular weight guest compounds, especially nonlinear optical (NLO) dyes, within the matrix of an amphotropic spacer polymer have been prepared. The polymer matrix enabled the transfer of guest compounds not capable of self-organizing at the air-water interface by themselves. The structure of the LB multilayers and the transfer process were studied by small angle X-ray scattering and UV-visible spectroscopy. Good NLO coefficients were found in the mixed films.

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…

Amphiphilic dyes for nonlinear optics: Dependence of second harmonic generation on functional group substitution