High-valent manganese in polyoxotungstates—II. Oxidation of the tetramanganese heteropolyanion [Mn4(H2O)2(PW9O34)2]10−☆

摘要: Abstract Oxidation of the heteropolyanion [Mn4II(H2O)2(PW9O34)2]10− (0) with potassium persulphate yielded mixed valence MnII,III products reproducibly isolated as green salt [Mn4(H2O)2(PW9O34)2]9− (1) and brown potassium-caesium [Mn4(OH)2(PW9O34)2]9− (2). Coulometric single crystal X-ray structure analysis revealed that 1 2 are one- three-electron oxidized derivatives 0 isostructural 0. Slight metrical variations among 0, appear in some MnO bond distances, which suggest oxidation has occurred first at aquated Mn(2) centres The magnetic susceptibility between 300 K shows Curie-Weiss law behaviour, θ = −27.35 K, without maximum for χ T ≈ 16 previously observed