The Anderson‐Type Anion (TeMo6O24)6− − A Multidentate Ligand for Trivalent Rare Earth Cations

The syntheses and structural characterizations of four novel lanthanide polyoxomolybdates containing the Anderson‐type anion (TeMo6O24)6− are presented. Depending on the size of the trivalent rare earth cations, in the solid‐state structures of {[La(H2O)6]2(TeMo6O24)}n·6nH2O (1), {[Ce(H2O)7]2(TeMo6O24)}n·7nH2O (2), {[Pr(H2O)7]2(TeMo6O24)}n·8nH2O (3) and {[Nd(H2O)7]2(TeMo6O24)}n·8nH2O (4) two different arrangements of the building unit are present. The (TeMo6O24)6− anion acts as a hexadentate ligand for LaIII and as a tetradentate ligand for CeIII, PrIII and NdIII, leading to two different infinite one‐dimensional chains. The crystal structures of the new compounds are compared with known lanthanide polyoxomolybdates containing the (TeMo6O24)6− anion and the influence of the LnIII ionic radii is discussed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)