Inspired by the ferromagnetic coupling in the cubane model (CaMn3O4)-O-IV of the oxygen-evolving complex of photosystem II, 3d-4f mixed-metal DyMn3O4 dusters were prepared for investigation of the magnetic properties. For comparison, (YMn3O4)-O-IV and (YMn2MnO4)-Mn-IV-O-III dusters were investigated as well and showed ferromagnetic interactions, like the calcium analogue. (DyMn3O4)-O-IV displays single-molecule-magnet properties, while the one-electron-reduced species ((DyMn2MnO4)-Mn-IV-O-III) does not, despite the presence of a Mn-III center with higher spin and single-ion anisotropy.