A pure inorganic 2-D framework based on paradodecatungstate and Mn<sup>2+</sup> ions: syntheses, structure, and properties

<div><p>A pure inorganic 2-D framework based on paradodecatungstate polyanions and [Mn(H<sub>2</sub>O)<sub><i>n</i></sub>]<sup>2+</sup> (<i>n</i> = 2, 3) ions, Na<sub>10</sub>{[Mn(H<sub>2</sub>O)<sub>3</sub>]<sub>2</sub>[H<sub>2</sub>W<sub>12</sub>O<sub>42</sub>]}{[Mn(H<sub>2</sub>O)<sub>3</sub>]<sub>2</sub>[Mn(H<sub>2</sub>O)<sub>4</sub>][H<sub>2</sub>W<sub>12</sub>O<sub>42</sub>]}·56H<sub>2</sub>O (<b>1</b>), has been synthesized and characterized by IR spectra, UV–vis spectra, thermogravimetric analysis (TGA), single-crystal X-ray diffraction, and magnetic measurements. Single-crystal X-ray diffraction analysis indicates that [H<sub>2</sub>W<sub>12</sub>O<sub>42</sub>]<sup>10−</sup> in <b>1</b> is a tetradentate ligand and coordinates to four [(Mn(H<sub>2</sub>O)<sub>3</sub>]<sup>2+</sup> cations through terminal oxygens to form manganese doubly bridged 1-D chains, which are further linked through [Mn(H<sub>2</sub>O)<sub>4</sub>]<sup>2+</sup> ions into a 2-D layer. The catalytic activities of <b>1</b> are tested in the selective oxidation of benzyl alcohol to benzaldehyde with 30% aqueous H<sub>2</sub>O<sub>2</sub> as oxidant in toluene, exhibiting 90% conversion and 93% selectivity. Magnetic studies indicate that weak antiferromagnetic couplings exist between the Mn(II) ions in <b>1</b>.</p></div>