Ligand exchange where one carboxylate is replaced by another carboxylate is an interesting way to change the cluster structure and/or functionality. Pucherberger et al. previously studied the exchange between methacrylate and propionate/acetate on zirconium oxo clusters by NMR. They inferred that, at room temperature, the monomer and dimer cannot be converted in one another and that the inter-cluster bridging ligands are unavailable for exchange. Here, we re-evaluate the ligand exchange process under more forcing conditions and apply our characterization toolbox to elucidate the cluster structure. Starting from the Zr12-acetate cluster, we stir it with 1.5 equivalents of new ligand (a carboxylic acid from Scheme 1) at 70 • C before we evaporate all volatile species. Since acetic acid has a reasonably low boiling point, it is readily removed from the reaction mixture, forcing the ligand exchange to proceed to completion (confirmed by the absence of acetate signals in the C NMR, see Figure ). The clusters are then purified to remove the excess of high boiling ligand. Model-free PDF analysis of the clusters shows that the dimer is obtained for butanoate, hexanoate, octanoate, decanoate, dodecanoate and oleate, see Figure . The Zr6 monomer is retrieved for methylbutanoate or methylheptanoate, showing that the dimer can be broken up under appropriate conditions and with the right structure-directing ligand.