Two novel trivacant Keggin-type polytungstates supported manganese carbonyl derivatives synthesized by degradation of metastable [γ-XW10O36]8− (X = GeIV, SiIV)

Abstract

Two novel trivacant Keggin-type polyoxometallate-based manganese carbonyl derivatives K₈[(OC)₃Mn(A-α-H₂GeW₉O₃₄)]·10H₂O (1) and K₈[(OC)₃Mn(A-α-H₂SiW₉O₃₄)]·11H₂O (2) have been synthesized by degradation of the metastable [γ-XW₁₀O₃₆]⁸⁻ (X = Ge^IV, Si^IV) in CH₃CN–H₂O solvent (1 : 2, vol.) and structurally characterized by elemental analyses, IR spectra, thermogravimetric analysis, and single-crystal X-ray diffraction. X-ray diffraction analyses indicate that 1 and 2 are isomorphic and consist of a [(OC)₃Mn]⁺ group and a trivacant [A-α-H₂XW₉O₃₄]⁸⁻ fragment, which exhibit the first examples of trivacant Keggin-type metal carbonyl derivatives. Additionally, the electrocatalytic properties of both for NO₂⁻ oxidation have been investigated.