Soluble poly(p-phenylene)s substituted with flexible side chains and low molecular weight model compounds were used for adsorption studies on gold and copper. The formed layers were analyzed with contact angle measurements, ellipsometry, infrared spectroscopy at grazing incidence, X-ray photoelectron spectroscopy, and surface profilometry. The state of the monolayer is not influenced by the rigidity of the polymer backbone alone, but also by factors such as the substrate and functional groups in the side chains. For some systems, uniform monolayers are obtained; i.e., the substrate is covered "completely" in these cases. Mostly, the data are consistent with the assumption of monolayers; occasionally ’thick" adsorbed layers form on copper. The results suggest that many of the adsorbed molecules coordinate to the substrates via eta2- or eta4-arene moieties.