A pure inorganic 2-D framework based on paradodecatungstate and Mn2+ ions: syntheses,structure, and properties

A pure inorganic 2-D framework based on paradodecatungstate polyanions and Mn(H₂O)_n]²⁺ (n = 2, 3) ions, Na₁₀{Mn(H₂O)₃]₂H₂W₁₂O₄₂]}{Mn(H₂O)₃]₂Mn(H₂O)₄]H₂W₁₂O₄₂]}·56H₂O (1), 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 H₂W₁₂O₄₂]^10? in 1 is a tetradentate ligand and coordinates to four (Mn(H₂O)₃]²⁺ cations through terminal oxygens to form manganese doubly bridged 1-D chains, which are further linked through Mn(H₂O)₄]²⁺ ions into a 2-D layer. The catalytic activities of 1 are tested in the selective oxidation of benzyl alcohol to benzaldehyde with 30% aqueous H₂O₂ as oxidant in toluene, exhibiting 90% conversion and 93% selectivity. Magnetic studies indicate that weak antiferromagnetic couplings exist between the Mn(II) ions in 1.