SELF-ASSEMBLY OF NONLINEAR-OPTICAL CHROMOPHORIC LAYERS THROUGH THE IONIC INTERACTION

The ionic attraction was applied to construct nonlinear optical (NLO) chromophoric layers. In order to fully utilize such an interaction, stilbene-type NLO chromophores having an anionic group at one end of the chromophores were designed. Among such type of the chromophores, trans-4'-(4-sulfonic acid sodium salt)butanoxystyrylpyridine (1) was synthesized. The pyridine moiety of the chromophore can be easily methylated to augment the molecular hyperpolarizability (beta). The above anionic chromophore self-assembles on the cationic surface, which is prepared by treating clean fused silica surface with 3-aminopropyltriethoxysilane and subsequently iodomethane. Characteristics of the molecular layer have been examined with contact angle measurement, UV-Vis spectroscopy, grazing angle FTIR spectroscopy, and NLO property measurement.