| Abstract
| - Three new homo- and heterometallic hexanuclear complexes [Mn2MII4O2(PhCOO)10(DMF)4] (with M = Mn (1), Co(2) or Ni (3) and DMF = dimethylformamide) have been synthesized by redox generation of benzoate ligands frombenzaldehyde in a one-pot reaction. All of the compounds are isostructural and crystallize in the I-42d space groupof the tetragonal system, data for 1: a = 27.2249(8) Å, c = 25.5182(5) Å, R1 = 0.0681. The crystal structurecontains isolated molecules. Each molecule consists of 2 × MnIII surrounded by four MII ions to form two edge-sharing OMn2M2 tetrahedra giving rise to the [Mn2M4O2] core. The coordination sphere of each metal is completedby the bridging benzoate ligands and DMF molecules. The magnetic susceptibilities of 1−3 have been measuredin the 1.8 K < T< 300 K temperature range. The magnetic susceptibilities for 1 and 2 pass through a broadmaximum at low temperature which is characteristic of the diamagnetic ground state, while for 3 no maximum isdetected down to 1.8 K. The magnetic data have been interpreted quantitatively for 1 and 3 on the basis of spinexchange interactions between the metallic centers (spin Hamiltonian for a pair being HAB = −JABSA·SB). Single-crystal measurements on [Mn6O2(PhCOO)10(CH3CN)4] (4) show that significant magnetic anisotropy develops atlow temperature.
- Three new complexes containing a [MnIII2MII4, M = Mn, Co, Ni] core have been easily synthesized by a novel method based on the in situ generation of benzoate ligands from benzaldehyde. Their crystal structures and magnetic properties are reported.
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