Organo-metal complexes have been self-assembled into thin monomolecular films by adsorption onto polyelectrolyte covered substrates. The basic molecular building blocks of these systems consist of octahedral coordinating metal ions (Cu(II), Co(II), Zn(II), and Hg(II)) and terpyridines or fused terpyridines, held together by non-covalent interactions. The structure of the films has been characterized by synchroton based X-ray reflectivity and fluorescence techniques, clearly proving the successfull deposition of a close-packed monomolecular layer of complexes. First results of diffuse X-ray scattering indicate that the complexes exhibit no long-range lateral order, while however, forming a laterally homogeneous film.