We have studied the adsorption of decacyclene (DC) molecules on a Cu(110) surface. The results are compared to previous studies of hexa-tert-butyl decacyclene (HtBDC) also on Cu(110). Opposite to HtBDC, the DC molecules do not induce any restructuring of the Cu(110) surface and no ordered structures are observed at low coverages. This difference is discussed in terms of molecule-substrate and molecule-molecule interactions. Close to full monolayer coverage, DC molecules are forced into ordered arrangements. The ordered structures with different molecule density are described in a model.