Double Sandwich Polyoxometalate and Its Fe(III) Substituted Derivative, [As₂Fe₅Mo₂₁O₈₂]^17– and [As₂Fe₆Mo₂₀O₈₀(H₂O)₂]^16–

A double sandwich polyoxometalate and its Fe­(III) substituted derivative, [As₂Fe₅Mo₂₁O₈₂]^17– (<b>1</b>) and [As₂Fe₆Mo₂₀O₈₀(H₂O)₂]^16– (<b>2</b>), were synthesized and characterized by single-crystal X-ray diffraction, infrared spectroscopy, fluorescent spectroscopy, UV spectra, thermogravimetry-differential scanning calorimetry analyses, electrospray ionization mass spectrometry, and magnetism measurements. The polyoxoanion is composed of a central fragment FeMo₇O₂₈ for <b>1</b> (Fe₂Mo₆O₂₆(H₂O)₂ for <b>2</b>) and two external AsMo₇O₂₇ fragments linked together by two distinct edge-sharing dimeric clusters Fe₂O₁₀ to lead to a <i>C</i>_2<i>v</i> molecular symmetry. The central FeMo₇O₂₈ fragment and external AsMo₇O₂₇ fragment have a similar structure, and both of them can be viewed as a monocapped hexavacant α-Keggin subunit with a central FeO₄ group or a central AsO₃ group. Both of the polyoxoanions contain a oxo-bridged Fe^III₅ magnetic core with the angles of Fe–O–Fe in the range of 96.4(4)–125.7(5)°, and magnetism measurements show an overall ferromagnetic interactions among the five-nuclearity cluster Fe₅ with the spin ground state <i>S</i> = 15/2

Double Sandwich Polyoxometalate and Its Fe(III) Substituted Derivative, [As₂Fe₅Mo₂₁O₈₂]^17– and [As₂Fe₆Mo₂₀O₈₀(H₂O)₂]^16–

A double sandwich polyoxometalate and its Fe­(III) substituted derivative, [As₂Fe₅Mo₂₁O₈₂]^17– (<b>1</b>) and [As₂Fe₆Mo₂₀O₈₀(H₂O)₂]^16– (<b>2</b>), were synthesized and characterized by single-crystal X-ray diffraction, infrared spectroscopy, fluorescent spectroscopy, UV spectra, thermogravimetry-differential scanning calorimetry analyses, electrospray ionization mass spectrometry, and magnetism measurements. The polyoxoanion is composed of a central fragment FeMo₇O₂₈ for <b>1</b> (Fe₂Mo₆O₂₆(H₂O)₂ for <b>2</b>) and two external AsMo₇O₂₇ fragments linked together by two distinct edge-sharing dimeric clusters Fe₂O₁₀ to lead to a <i>C</i>_2<i>v</i> molecular symmetry. The central FeMo₇O₂₈ fragment and external AsMo₇O₂₇ fragment have a similar structure, and both of them can be viewed as a monocapped hexavacant α-Keggin subunit with a central FeO₄ group or a central AsO₃ group. Both of the polyoxoanions contain a oxo-bridged Fe^III₅ magnetic core with the angles of Fe–O–Fe in the range of 96.4(4)–125.7(5)°, and magnetism measurements show an overall ferromagnetic interactions among the five-nuclearity cluster Fe₅ with the spin ground state <i>S</i> = 15/2

Double Sandwich Polyoxometalate and Its Fe(III) Substituted Derivative, [As₂Fe₅Mo₂₁O₈₂]^17– and [As₂Fe₆Mo₂₀O₈₀(H₂O)₂]^16–

A double sandwich polyoxometalate and its Fe­(III) substituted derivative, [As₂Fe₅Mo₂₁O₈₂]^17– (<b>1</b>) and [As₂Fe₆Mo₂₀O₈₀(H₂O)₂]^16– (<b>2</b>), were synthesized and characterized by single-crystal X-ray diffraction, infrared spectroscopy, fluorescent spectroscopy, UV spectra, thermogravimetry-differential scanning calorimetry analyses, electrospray ionization mass spectrometry, and magnetism measurements. The polyoxoanion is composed of a central fragment FeMo₇O₂₈ for <b>1</b> (Fe₂Mo₆O₂₆(H₂O)₂ for <b>2</b>) and two external AsMo₇O₂₇ fragments linked together by two distinct edge-sharing dimeric clusters Fe₂O₁₀ to lead to a <i>C</i>_2<i>v</i> molecular symmetry. The central FeMo₇O₂₈ fragment and external AsMo₇O₂₇ fragment have a similar structure, and both of them can be viewed as a monocapped hexavacant α-Keggin subunit with a central FeO₄ group or a central AsO₃ group. Both of the polyoxoanions contain a oxo-bridged Fe^III₅ magnetic core with the angles of Fe–O–Fe in the range of 96.4(4)–125.7(5)°, and magnetism measurements show an overall ferromagnetic interactions among the five-nuclearity cluster Fe₅ with the spin ground state <i>S</i> = 15/2

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

<div><p>A pure inorganic 2-D framework based on paradodecatungstate polyanions and [Mn(H₂O)_<i>n</i>]²⁺ (<i>n</i> = 2, 3) ions, Na₁₀{[Mn(H₂O)₃]₂[H₂W₁₂O₄₂]}{[Mn(H₂O)₃]₂[Mn(H₂O)₄][H₂W₁₂O₄₂]}·56H₂O (<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 [H₂W₁₂O₄₂]¹⁰⁻ in <b>1</b> 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 <b>1</b> 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 <b>1</b>.</p></div