Stable Langmuir monolayer of arachidic acid (AA) was formed on a subphase of tris (1, 10-phenanthroline) ruthenium(II) [Ru(II)] aqueous solution. π-A isotherm and dynamic elasticity measurements indicated that the monolayer was more condensable than that on pure water due to the electrostatic interaction between AA and Ru(II) ions and would aggregate in solid-like state. Y-type AA LB films containing the photofunctional ions, Ru(II) were deposited successfully and characterized by UV-visible and low angle X-ray diffraction spectra respectively. It was proved that the obtained AA-Ru(II) LB films were stable, homogeneous and sandwich-like multilayers, in which the relatively stable AA-Ru(II) groups aggregated to form J-aggregate in each layer.

Key words: RUTHENIUM COMPLEX, CHELATES, ELASTICITY, Arachidic Acid