SYNTHESIS AND CHARACTERIZATION OF NEW LIQUID-CRYSTALLINE DYES FOR NONLINEAR OPTICS

Abstract

We present the synthesis and a description of the physical properties of several organic dyes containing stilbene as well as azomethine groups. The preparations of all compounds started from a common precursor, 4-amino-4'-nitrostilbene, followed by condensation with aromatic aldehydes. The mesomorphic properties and spectroscopic data were established using polarizing microscopy, DSC measurements, X-ray and UV/Vis spectroscopy. Three of the compounds showed enantiotropic smectic phases, two of them highly ordered S(E) and S(B) phases, and a nematic phase. In addition quantum chemical calculations concerning the electronic properties were carried out.