An Inorganic Aggregate Based on a Sandwich-Type Polyoxometalate with Lanthanide and Potassium Cations: From 1D Chiral Ladder-Like Chains to a 3D Open Framework

The reaction of sandwich-type polyanion [Mn4Si2W18O68(H2O)2]12–, ceric sulfate, and potassium citrate in an acidic aqueous solution led to the isolation of a new compound K4Na2[{Ce(H2O)7}2Mn4Si2W18O68(H2O)2]·21.5H2O (1), which crystallizes in the space group P212121 with a = 12.040(2) A, b = 26.094(5) A, c = 30.043(6) A, V = 9439(3) A3, Z = 4, and flack parameter x = 0.63(1). X-ray diffraction analysis reveals that 1 consists of novel chiral ladder-like chains based on sandwich-type polyanions and lanthanide cations, which are further connected into a three-dimensional open framework by potassium cations.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)