Two organic–inorganic hybrid materials based on the penta-nuclear {MMn4} (M = W and Mo) heterometallic clusters and Schiff-base ligands

Two organic–inorganic hybrid compounds with the formula {[MnIII(Salen)(H2O)]4MoO4}·Cl2·16H2O (1) and {[MnIII(Salen)(H2O)]4WO4}·(CH3COO)2·11H2O (2) (Salen = Di-[2-hydroxyl-3-methoxyl-benzaldehyde] ethylenediamine) have been synthesized and structurally characterized by IR, UV–vis spectroscopy, TG analysis and single crystal X-ray diffraction. Structural analysis revealed that compounds 1 and 2 consist of a [MoO4]2 − or [WO4]2 − building unit and four {[MnIII(Salen)(H2O)]+ metal–organic moieties, respectively. In the crystal structure, the [MoO4]2 − or [WO4]2 − tetrahedra coordinated with four MnIII ions, resulting in the penta-nuclear heterometallic tetrahedra cluster compounds, which were rarely observed in the Mn-Salen system. Magnetic study revealed that there was antiferromagnetic coupling in the two compounds.