The reaction of [Ru 3 (CO) 12 ] with pivalic acid in acetonitrile afforded the coordinatively unsaturated complex [{Ru 2 (μ-O 2 C t Bu) 2 (CO) 4 } n ] (1) for which a so far unknown polymeric structure is assumed. Compound 1 showed in the solid as well as dissolved in non-polar aliphatic solvents and carbon tetrachloride, respectively, a deep violet color. In common organic solvents 1 is readily dissolved resulting in solutions exhibiting a yellow to orange color. On the one hand, in such solutions the polymeric structure of 1 is broken resulting in distinct compounds as the Ru 2 (μ-O 2 C t Bu) 2 (CO) 4 units coordinate two monodentate solvent molecules, as shown for [Ru 2 (μ-O 2 C t Bu) 2 (CO) 4 (py) 2 ] (3, py = pyridine), or they coordinate ligands like phosphanes, as shown for [Ru 2 (μ-O 2 C t Bu) 2 (CO) 4 (P t Bu 2 H) 2 ] (4). On the other hand, in solutions of 1 the Ru 2 frameworks are linked by coordination of multidentate solvent molecules resulting in a coordination polymer which was confirmed by the crystal structure determination of [{Ru 2 (μ-O 2 C t Bu) 2 (CO) 4 (HOC 2 H 4 OEt)} n ] (2).