A surfactant ion-pair complex, [Ru(bpy)(2)L][Eu(NTA)(4)](2) (in which L = 1-docosyl-2-(2- pyridyl)benzimidazole, bpy = 2,2'-bipyridine, and NTA = 4,4,4-trifluoro-1-(2-naphthyl)-1,3-butanedionato) has been synthesized. The surface pressure-area isotherm measurements show that the complex forms a stable Langmuir film at the air-water interface without adding any electrolytes into the subphase. The monolayers formed at the surface pressures of 5 mN m(-1) and 20 mN m(-1), have been successfully transferred onto glass and quartz substrates with the transfer ratios close to unity. The Langmuir-Blodgett films were studied by UV-visible, infrared, and emission spectroscopies, atomic force microscopy, and cyclic voltammetry. The optical, redox, and morphology properties of the LB films were found to be significantly affected by the target surface pressures used for the film depositions.