Effect of the Mn Oxidation State on Single-Molecule-Magnet Properties: MnIII vs MnIV in Biologically Inspired DyMn3O4 Cubanes

Inspired by the ferromagnetic coupling in the cubane model CaMnIV3O4 of the oxygen-evolving complex of photosystem II, 3d–4f mixed-metal DyMn3O4 clusters were prepared for investigation of the magnetic properties. For comparison, YMnIV3O4 and YMnIV2MnIIIO4 clusters were investigated as well and showed ferromagnetic interactions, like the calcium analogue. DyMnIV3O4 displays single-molecule-magnet properties, while the one-electron-reduced species (DyMnIV2MnIIIO4) does not, despite the presence of a MnIII center with higher spin and single-ion anisotropy.