New Synthetic Route toward Heterometallic 3d–3d′ and 3d–4f Single-Molecule Magnets. The First Co^II–Mn^III Heterometallic Complex

Four tetranuclear heterometallic complexes, [CoII2Mn2III(dpm)4(MeO)6] (1) and [LnIII2­MnIII2­(dpm)6­(MeO)6(MeOH)n], where Ln = Gd (2, n = 2), Tb (3, n = 2), and Dy (4, n = 0), have been obtained following the same general synthetic route, namely, the one-pot reaction between 2,2,6,6-tetrametil-3,5-heptanodione (Hdpm), MnCl2 and CoCl2 or Ln­(NO3)3 in the presence of sodium methoxide. Within the four compounds, the metal ions bridged by methoxide ligands display a defect-diheterocubane core. Compounds 1, 3, and 4 show slow relaxation of the magnetization below 4 K.