It is also interesting to compare the measured electronic properties of adsorbates as a function of the underlying substrate. Within this work, the common product on which to perform such comparison is d2, and the associated data are displayed in Figure . On both surfaces, the dI/dV spectra reveal clear resonances for the HOMO-1, HOMO and LUMO orbitals. However, there are substantial differences between the two gold surfaces. Taking the on Au(111) as reference, we see a substantial downward shift in the energy of all molecular orbitals of molecules adsorbed on Au(110). This effect could in principle be ascribed to the different workfunction of the two gold surfaces, which is lower by about 170 meV for Au(110). In an ideal vacuum level pinning scenario, as expected for weakly interacting molecule-substrate interfaces, this would translate into a rigid downward shift of all molecular orbitals by that amount. However, whereas the HOMO and HOMO-1 indeed shift rigidly by that same amount, the LUMO shifts substantially more, resulting in a reduction of the HOMO-LUMO gap by nearly 0.5 eV. We hypothesize that, although maintaining a weak adsorbate-substrate electronic coupling and thus showing no obvious changes in the conductance maps of the orbitals, the larger shift of the LUMO may result from a slightly increased hybridization of the unoccupied molecular orbitals with the undercoordinated (and thus more reactive) Au atoms that form the rows of the Au(110) reconstruction and cause the molecule's tilting. Furthermore, the gap reduction is also compatible with a larger role of the electronic screening induced by the substrate, which is consistent with the position of the molecules inside the trenches of the surface reconstruction.