The Anderson‐Type Anion (TeMo 6 O 24 ) 6− − A Multidentate Ligand for Trivalent Rare Earth Cations

The syntheses and structural characterizations of four novel lanthanide polyoxomolybdates containing the Anderson‐type anion (TeMo 6 O 24 ) 6− are presented. Depending on the size of the trivalent rare earth cations, in the solid‐state structures of {[La(H 2 O) 6 ] 2 (TeMo 6 O 24 )} n ·6 n H 2 O ( 1 ), {[Ce(H 2 O) 7 ] 2 (TeMo 6 O 24 )} n ·7 n H 2 O ( 2 ), {[Pr(H 2 O) 7 ] 2 (TeMo 6 O 24 )} n ·8 n H 2 O ( 3 ) and {[Nd(H 2 O) 7 ] 2 (TeMo 6 O 24 )} n ·8 n H 2 O ( 4 ) two different arrangements of the building unit are present. The (TeMo 6 O 24 ) 6− anion acts as a hexadentate ligand for La III and as a tetradentate ligand for Ce III , Pr III and Nd III , leading to two different infinite one‐dimensional chains. The crystal structures of the new compounds are compared with known lanthanide polyoxomolybdates containing the (TeMo 6 O 24 ) 6− anion and the influence of the Ln III ionic radii is discussed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)