Devices built from quantum-dot cellular automata (QCA) use cells with bistable charge configurations to represent binary information. Coulomb interactions between cells allow the state of one cell to affect that of another, and can be used to construct more advanced QCA devices, such as binary wires, inverters, and logic gates. Molecular QCA cells, with their sizes at the nanometer scale, are predicted to be able to function at room temperature. A dinuclear organometallic molecule, trans-[Cl(dppe)2Ru(CÌÄå¢Ì¢åÛå¡ÌâåÁC)6Ru(dppe)2Cl] (Ru2), is a candidate for use in molecular QCA devices when it is singly oxidized to the mixed-valence Ru2+[PF6]-. These molecules were studied by ultra-high-vacuum scanning tunneling microscopy (UHV-STM) at room and low temperatures. Ru2 was pulse deposited onto the Au(111) surface under vacuum. Isolated Ru2 molecules were successfully imaged by STM on Au(111) at room temperature. However, STM images were degraded by mobile toluene solvent molecules that remain on the surface after the deposition. Cooling the sample to 77 K allows solvent molecules to be observed directly using STM, and under these conditions, toluene forms organized striped domains. Although pulse deposition is an effective way to deposit molecules on surfaces, the presence of solvent on the surface after pulse deposition is unavoidable without thermal annealing, and this annealing causes undesired chemical changes in the adsorbates under study. Submolecular structure of Ru2 was clearly discernible in STM images at room temperature, with a bright feature corresponding to each of the two Ru-centered end groups within each Ru2 molecule. The adsorption of Ru2 was found to have some degree of orientation preference on Au(111) at room temperature. Rotation and translation of Ru2 molecules were induced by the STM tip under some tunneling conditions. At 77 K, Ru2 and Ru2+[PF6]- both form close-packed islands with organized striped patterns on Au(111). For neutral Ru2, all end groups show uniform contrast and the two end groups within each Ru2 molecule are almost indistinguishable. The two end groups of each Ru2+[PF6]- molecule, show clearly discernible contrast differences in STM images. We believe the contrast difference results from the different valence state of the Ru metal atoms in the end groups: one of them is Ru(III), while the other is Ru(II). Near each Ru(III)-centered end group, a small feature was found in STM images and assigned as the counterion [PF6]-. Increasing the sample bias from -1.0 V to 1.0 V attenuates the STM contrast of the charged end groups of Ru2+. This contrast changes result from the different molecular orbitals responsible for the tunneling current under various tip-sample bias voltages. Similar striped monolayers of Ru2+[PF6]- on Au(111) are also observed at liquid helium temperature.