AMPHIPHILIC NONLINEAR-OPTICAL BIS-CHROMOPHORES AND THEIR MIXTURES WITH AMPHOTROPIC COPOLYMERS - PREPARATION OF MONOLAYERS AND LANGMUIR-BLODGETT MULTILAYERS

A new type of bis-chromophores containing two successive, covalently linked, nonlinear optical (NLO) dyes has been synthesized. For their preparation, alpha-cyanocinnamates or dinitrophenylhydrazones have been combined with an 4'-alkoxybiphenyl-4-carboxylate acting both as a hydrophobic, mesogenic moiety and as the second NLO dye. The self-organizing properties at the air-water interface as well as the monolayer and LB multilayer transfer of these new NLO amphiphiles has been investigated. Furthermore, stable and homogeneous mixed films with an amphotropic matrix polymer were obtained due to the enhanced miscibility of the mesogenic dye with the mesogenic side chains of the polymer. Second harmonic generation (SHG) measurements have been carried out, showing the complex behavior of the molecules.