Quantum mechanical calculations at the density functional theory (DFT) level have been performed on diruthenium tetracarboxylates of different levels of molecular complexity: from unsolvated monomers to oligomers. The agreement between the calculated and experimental molecular structures and vibrational modes of the simple [Ru-2(mu-O2CCH3)(4)](0/+) and [Ru-2(mu-O2CCH3)(4)(H2O)(2)](0/+) systems made us confident in our calculation methodology. Therefore, it has been applied to the analysis of two different kinds of properties of these compounds: the trends in the UV/vis spectroscopy and electrochemistry along the [Ru-2(mu-O2CCH3)(4)X-2](-) (X = Cl-, Br-, I-) series, and the crystalline polymorphism related to the polymeric strand conformation in extended Ru-2(mu-O2CR)(4)Cl compounds. For the [Ru-2(mu-O2CCH3)(4)X-2](-) series, we report new spectroscopic and electrochemical results and interpret the trends on the basis of time dependent DFT-polarized continuum model calculations, local charge and spin analysis, and X donor properties. As far as the polymeric conformation is concerned, it has been previously suggested that the Ru-Cl-Ru angle results from a compromise between packing, orbital overlap, and microsegregation. Our calculations on [Ru-2(mu-O2CCH3)(4)Cl](2)Cl- and [Ru-2(mu-O2CCH3)(4)Cl](3)Cl- oligomers provide insights on the influence of the first two factors on the strand conformation and allows a suggestion on what is the equatorial aliphatic chain's influence on this issue.