Magnetic "Molecular Oligomers" Based on Decametallic Supertetrahedra: A Giant Mn49 Cuboctahedron and its Mn25Na4 Fragment

Two nanosized Mn and MnNa clusters based on analogues of the high-spin (S=22) [MnMn(?-O)] supertetrahedral core are reported. Mn and MnNa complexes consist of eight and four decametallic supertetrahedral subunits, respectively, display high virtual symmetry (O), and are unique examples of clusters based on a large number of tightly linked high nuclearity magnetic units. The complexes also have large spin ground-state values (Mn: S=61/2; MnNa: S=51/2) with the Mn cluster displaying single-molecule magnet (SMM) behavior and being the second largest reported homometallic SMM.